I've seen rebuild kits available in the US for the A341E auto's found in the 2JZ TT Supra and the 1UZ Soarers. The kit is designed to handle the crazy outputs that people tweak their 2JZ TT's upto. It was around US$800 from memory for the entire kit, clutches, bearings, seal, VB mods etc etc. Seems good value to me if you're up to the task of stripping down your gearbox. I've had my A341E in complete bits, it's not a terribly hard job just a bit time consuming.
I've since bought the genuine Toyoyta repair/overhual mamual for it.