Requires adapters for the calipers
Front Rotor should be 30mm wide, requires I don't know what factory rotor, not sure if the 993-996 stuff fits the old hubs?
Rear Rotor is a 24mm wide unit. 86-89 911 Carrera Rear Rotors work, which you might all ready have.
Rebel Racing makes a complete kit to do what your doing. You will need to mix and match a few things with 911 parts, nothing new just use the Porsche lego system. They will gladly help you get the correct parts for the job.
You will also need a 22-23mm master cylinder. The one you have will most likely be a 19mm, pedal will go to the floor before it moves the pistons in the caliper enough to engage the rotors to stop the car.
Ad it will require 16 inch wheels maybe, you will need to check fitment. 17" should fit. If using later model 993-996 Boxster what ever wheels will require spacers.
Slippery slope, lots of money in brakes that are not needed unless your making uber HP, and running at really high speeds. There is something to be said for seeing huge brakes on a car. And all modern sports car use huge brakes. But think where we have come in tire technology, ABS, and litigation. Tires have improved, ABS allows the layperson not to get in over their head, and well the lawyers being lawyers, have made sure a manufacture can not put drum brakes on a car. It must stop 100% of the time, even when the 99.99% it is not the manufactures fault.
So you know I am on this slope, and navigating its terrain currently and I think I am
for doing it. Really good deal on the 996 calipers has caused me to shell out to get them on the car. Needed something to fill the 17" rims, yeah thats it. We creates our reality.