Oooo a manual swap thread 8)
Don't forget the driveshaft

The TKO500/600 is for more of a direct swap-type deal, they have the standard old-school bolt patterns (Ford, GM, Chrysler, etc.).
The T56 is rated somewhere around 450lbs/ft from GM, Viper T56s are stronger but the input shaft has to be changed I think. There is a T56 'Magnum' that came out from Tremec rated at 700lbs/ft, and is also cheaper than the 6-speed Richmond (~$2,800 on Summit's site).
Want to make things more interesting?
http://www.keislerauto.com/recent-news/the-all-new-road-a-track-6-speed.html