You probably don't want the stock toyota brakes. They are very unpredictable. There is a guy who does special work to them, to make sure the pistons slide easy which helps improve the brakes. There are also brake pads from brakeman that are very good. I can't remember the guy who does the work to the calipers and pistons, I can get his name if you like.
I would actually recommend looking at Pro challenge stuff. They use wildwood disk brakes all the way around. Would require a different rear end though. Well, you could get your current toyota rear end modified, as that is what the pro challenge guys do. Pro challenge also sells a quick change rear end that might be of use to you as an autocrosser.