Check this site regarding different sizes and styles of coilovers:
Racerunner Shocks
A lot of us are running those, or Donahoes. There are a few guys running Kings, and Camburg uses Swayaway as their supplier. The 2.0/2.5 thing doesn't make a big difference unless you're really beating the hell out of it...I've found that I can blow a 2.0 when I'm running rough trails or moving fast with 6500# GVW (ie 500# over GVWR for my A/C--3500# front, 3000# rear)...they last about a week of severe punishment and then they need a rebuild. Going to a 2.5 would help me (maybe), but if you're not loading almost a literal ton of stuff on the truck and then punishing it, the 2.0 with the 7/8" shaft is a great shock, no need for an external reservoir. You can get any diameter body (2.0, 2.5, 3.0 etc) threaded for a coil spring as long as the body is designed for threads and has room for them.
Here's my two bucks...with your desires and divorce-threat-limited budget

, I'd skip the spacer route entirely and get this package deal from Gary Wheeler at Wheeler's Offroad:
Camburg Coilover Shocks and Upper Control Arms - Wheeler's Off-Road, Inc
Add the 5100s in the rear for a total $1380.
Get the upper ball joint press tool and a set of diff drop spacers from Total Chaos...you can order direct or go through Offroad Warehouse, but you need those parts. They are inexpensive...might be 50-60 bucks total for both.
So conservatively let's say that's 1500 bucks for all the parts you're likely to need for a
long time, since you can easily fit 33s with that setup.
Next skip the "somebody else's problem" money pit of the shop install and find a buddy with a garage if you don't have one yourself. The tools you'll need are inexpensive, just a breaker bar, torque wrench, ratchet wrench, metric socket assortment, 6" extension, all 1/2" drive stuff, plus a long 14mm wrench, a 14mm ratchet wrench, a 19mm regular and 19mm ratchet wrench (get the kind with the 180* swivel head!), floor jack and jack stands, 3' crowbar, and you're set...might cost you total 150$-200$ for tools, depending on the jack you buy and where you get the tools. The knowledge and experience you gain will be priceless! Don't hesitate to ask anyone here for tips, tricks, hints with the install. It's actually very, very easy. Don't forget shop towels, leather gloves, and vinyl or latex gloves to keep your hands clean...keeps your girl happy

. The diff drop spacers take a larger socket and wrench, but I forget offhand...there was a recent thread, do a search.
You can find decent looking "basic" wheels around 100 bucks a pop. Buy FIVE...don't get four and then be "that guy" with the goofy undersized spare tire...get a set of five rims and tires. You can find very nice rims for about 130-150 a hit. 33" tires will cost you anywhere from 130-180 each...if you get everything at the same place, you may be able to get out the door for 1200 mounted and balanced, trade your old tires for a hundred bucks, sell your old rims here for 250 or so...
or to save some cash keep your stock rims (or get takeoffs from an FJ or something, they look really good on a Tundra) and run a 255/85/16, that's a narrow 33, less rubbing, less expensive, taller by a hair than a 285/75/16, less rotating weight, no need to spend 500-700 on new rims, and they are trail proven by many, many people with Tacomas and Tundras. That's what Joe was running when he did Golden Crack and a bunch of other punishing trails out in Moab when his truck was still IFS. I would swear half the people on the Expedition Portal are running those tires.
Conservatively again, now you're at about 3K$ (or 2300$ if you used your stock rims), you have a complete setup ready for offroad that will handle excellent on-road, larger tires which you can air down for the trail, and a great looking rig that you'll be proud to drive, and you'll still have 2000$-2700$ left over (depending on the rims). Pick up a CO2 tank from Brian at
Ultimate Air for a couple bills, a pressure gauge for a buck fifty at the corner store, a tow strap, a Hi-Lift jack, cover and 4xRac (they rock, but buy your own mounting bolts!) and the all-important
Lift-Mate (don't leave home without this!) for about 100$-150$ total (Ebay!), and a set of recovery ladders (search in the Offroad subsection, I got mine from Amgrating.com but there's a guy who sells them precoated for a similar price) for around 200$, and a Bushranger X-Jack for about 200 bucks...all those trail pieces will run you up about 650$-700$ depending where you buy...and you'll still have something like 1500$ to spend on a skimpy cocktail dress, earrings and five star date to appease your wife (the dress and the earrings are for her, btw

), to which you can drive your now-badass truck

. Then take her out wheeling with you with a picnic lunch and I bet she likes it...then you're scot-free to mod as you please in the future

...if you're really lucky she'll even help you mod the truck

. Then you can say stuff like "
Honey, we really need a snorkel, it's for our family's safety." :clown:
You can take the RCD kit offroad, it's very sturdy, but you'll get better performance overall (on and offroad) by staying away from drop brackets and instead trimming to get tire clearance. For 33s, particularly 255/85/16s, all you really need is a hammer to work the pinch weld back, and you'll never rub. You can take spacers offroad, and stock-length aftermarket coilovers, but there's a huge performance difference between stock joints and uniballs...about 4" of front wheel travel. That's a lot considering you only start with about 6".
If you get coilovers and run them up to 4", you'll need a uniball to retain droop and decent ride quality, but it can be done. You'll still need to trim to fit 35s, but you'll easily clear 33s, even 33x12.5 if you want that instead of 33x10 (255/85/16). Since you have 4x4, if you want to run 4" lift, you'll also
need the diff drop spacers
and the 930 CV boots from Kartek, and the installation of the CV boots is either $$$$ at a shop or time and filth for you. It's not a cakewalk and very, very messy. You only need 2" to fit 33s anyway, BTW that's level for an access cab. If you want 2.5" in the front, grab an add-a-leaf...usually 50-100 bucks.
If you get a drop bracket and run 33s, they'll look small. Also if you get a drop bracket, you're back in to $$$$ and trouble with the wife, and for all the clearance you'll have you'll be a lot less comfortable when the trail takes a wicked lean, and you won't be able to corner as hard on pavement, and unless you're getting serious quality like the RCD anyway, you're looking at weak spindles and potential trouble in the future. Better to take a couple bills of what's left over, get the spindle gussets from Total Chaos and have a very experienced welder stitch them up. Your front end will look a lot like mine...see my main photo gallery...and if you look in my separate albums you'll see what I've taken that setup over and through...it's capable and durable, and has been holding up to 35s and punishment for a couple years now.
Save your money if you want 35s...by the time you're finished with lifts, trimming, wheels, all the little bandaids you'll need to fit them, you'll be in over 5K between the kit, the install, wheels and tires, regearing, etc...stick with 33s for now and enjoy the truck. The only way you can cheaply fit 35s is by taking about twenty hours with a sawzall, air body saw, die grinder, cutoff wheel, spare sheetmetal, a lot of wet towels, and a very competent welder. Note I don't have a drop bracket...that's 35s on about 3" of lift, or whatever it's settled to now. I don't really care about the height since nothing rubs unless it's REALLY twisted up while I'm turning the wheels

.
If you look through my main gallery you'll see a few older pictures when the truck was more stock...the filthy truck pic is a 2" front lift and nothing in the rear, with 33x11.5 (285/75/16) tires. The water crossing pic and the one with the green truck is with 2.5" in front, Alcan springs at 2.5" (probably more like 3", they hadn't settled yet and the bed was empty), and the green truck has a 3" body lift, 2" coilover lift and 35s. There are also pics of what I had to do for 35s and no drop bracket or body lift. It's not an easy process but IMHO more rewarding at finish than putting the truck on stilts to fit a big tire in front. With what I've done now, I should be able to sneak a 37 up there for road use and mild trails.
-Sean