+1 for the budget big brake kit. Been using it at trackdays for almost 2 years now, incredible improvements in braking force and ultimate heat capacity. c5 calipers are good, c6 calipers are marginally stiffer, but also thicker, and may not fit under the stock wheels like the c5 calipers do. Also, having access to every performance pad made for Corvette is nice.
I traded ride/drives with a friend who has the Wilwood kit on his manual swapped vic, he was impressed with my brakes, I was....not super impressed with his. Might be something about master cylinder sizing, idk.