In case you're still looking for the front brake upgrade, I just did the ITR caliper/pad & Mini rotors on my '00 RS.
This website is super useful and has many options available.
To be dead honest, I didn't do the front upgrade for "stopping" purposes as much as heat dissipation. You'll be able to put more heat through a larger rotor without affecting braking, and it'll dissipate the heat considerably faster due to the larger surface area. Not to say that braking hasn't improved as well, but it's definitely not comparable to something like a Wilwood/Brembo/Stoptech 2 or 4 piston setup. Sliding brakes won't do that.
Rear brakes aren't really even in the question for me - my car is a daily, but I also track it often in the summer. Rear brakes just don't get used enough to demand a considerable upgrade. If you're having that much trouble stopping the car, you either need to get better pads/rotors, or consider a different racing line