There is one other option out there that no one has mentioned... The 3.8 V6 from Buick. I know, I know, it's a domestic, and we'd all like to stay Toyota. But, there are a lot of 3.8's out there, you can buy conversion kits for them (even with 5 spd), and if you really want to go crazy, try to find one of the turbo 3.8's out of a Grand National or T-Type. There's power available there that could rival the turbo supra engine!