If you want a cheap upgrade that will make you brakes work very well and be reliable then that can be covered by using stock calipers, good blank rotors, a full ATE brake fluid flush, good brake pads HPS or better, replacement of the shims, clips, rubber boots for pins (Autozone brake hardware kit 20 bucks), and clean/regrease caliper guide pins.
From what I've heard, the C5 brake setup works very well. Though I think more of the benefit comes from the increased heat aborbing ability, and it is quite a bit heavier than stock brakes. It looks badass too. I use the above though with the stock brakes in my autox/speedway setup