Yeah, it's been done. The TRD
Supercharged Celica has had it done. I'm not ready to complete the task yet. I'm weighing cost/benefit ratio to see if it's worth the $$ ($1100 quoted price). Then again, I could just go with the SSBC brakes ($700), but I haven't heard too many good things from them. If I go with them, my rear brakes will be 1.4 inches lager in diameter than the front brakes. That might look kind of funny.
I'm thinking of looking for a wrecked GTS in the area salvage yards where I can get these parts for cheap, as long as I yank them off myself. At least now I know what I need to take.