Take a look at the selection on www.bigbrakeupgrade.com Lots of options using factory parts from other cars. Your options will be limited by the size of your wheels though. Most upgrades just don't fit under the stock wheels.

 

 

C5 brakes numerous threads on here about how to do the upgrade and on You tube, just search C5 brakes on here and thirdgen brake conversion on You tube fairly easy mod.

 

Your real issue will be if you still have the stock 16 inch GTA wheels on the car. Those restrict brake upgrade options more than any other 16 inch thirdgen wheel

 

I have stock brakes with Hawks pads and slotted and drilled rotors and and 4th gen rear discs 00 came with the stock 4 th gen 00 Trans Am rear. Also have c5 wheels so no clearance issues. I haven't done the c5 front conversion yet but I intend to.