Well I got it done. I scored a great deal on set of brand new leather seats complete with airbags for my crewmax from Dietdewguy who's company does alot of work for Toyota and had about 6 or 7 sets of brand new seats in both cloth and leather for both Crewmax and Double Cabs still on the pallet/in the box. (I believe his for sale post is still in the classifieds forum.
As many of you probably know the SR5's only came with a power driver seat and manual front passenger seat so the plugs are different. So I had a dillema to either figure a way to incorporate the power passenger seat or have the leather covers swapped over to my cloth passenger seat frame. The driver seat is truly plug and play. I figured it would be odd to have heated on the driver side (with addition of seat heater switch) but not on the front passenger side.
After searching the forum I read about a guy who accomplished this by swapping in the passenger side floor harness from a Limited, so I decided I would do the same. I purchased a passenger side floor harness online for $273.00 ($394 list) shipped. I installed it today and what a task it was. Took about 6 hours. The wiring harness goes from the passenger side kick panel then under the seat/carpet and up the B pillar to the side passenger rear door harness and up further to the passenger side curtain airbag (headliner had to be removed) and back to the C pillar and rear window regulator. There is also a wire/plug that runs under the center console (center console had to come out) to what appears to be the SRS control unit under the dash. Of course rear seats were just bolt in.
It was one hell of a project but I feel it was worth it. Now to sell my complete cloth set of seats and use the money to buy the seat heater switches and recover some of the money I spent on the leather set.
I now have a leather front passenger seat with power slide,recline and adjustable lumbar. I was going to take some pictures of the process to post a DIY but I got lazy.