Check out this site
www.urdusa.com It was started by a guy named gadget that seems to know his stuff about Toyota trucks. I think the V6 Tundra and Tacoma share this same engine so what ever he offers for the Tacoma should work with the Tundra. I'd ask him though. The upgrades he has are for supercharged Tacomas. It is basically an upgrade kit for the supercharger. Not sure if it's what you are looking for, but it may come out cheaper than the second option you were looking at.