FWIW, my Pantera has 15x8 and 15x10 wheels. It's equipped with four-piston Wilwood calipers, and approx 12x1.25 inch vented rotors (the lowest spec Wilwood offers, unfortunately). I originally had Wilwood's 'gator' pads (which were painted lime green). Those worked fine with power assist, but put out an awful amount of dust.
That was their 'best' compromise street/track pad in the early 90s, but times have changed. Wilwood has come up with what they call 'smart' pads, BP10 and BP20.
I have the BP20 pads, although in looking at their website, they don't list them anymore??? They were just slightly better than the BP10 which is still there.
Go here:
Wilwood High Performance Brake Pads
That shows all the different pad compounds available; you can also see graphs which chart coefficient of friction (Cf) versus temperature. The BP10 is especially linear, giving great friction (and most importantly, the SAME friction) across a very broad temperature range. Wilwood pads are manufactured by Raybestos, by the way.
In my 427 Cobra replica, I have the same Wilwood Superlite II calipers, but it is equipped with Hawk HP+ pads, which are also fantastic. The rotors are of unknown manufacture, but are about 12x1.25 inches also. The Hawks are terrific too, and again, have substantially less dust (and much better performance) than the green Gator pads it also had originally.
Although lots of people like to put huge sexy brakes on their cars, with rotors the size of dinner trays, the simple fact is that tires will always be the limiting factor; with these 'small' four-piston Wilwood calipers and 12-inch rotors, you will NEVER come close to running out of brakes. You will be able to perform max-effort stops again and again, and won't experience any measurable fade from the brakes; the tires will lock up before the brakes can absorb enough energy to get them hot enough to degrade measurably.
It's also worth mentioning that more isn't always better; the six-piston Wilwood calipers actually have a smaller surface area than the four-piston calipers, and thus have less 'grip' for a given amount of hydraulic (brake pedal) pressure. All of that can be dialed in if you are a math whiz and can calculate the surface area of your master cylinder piston(s) versus your brake caliper pistons. I just took the easy way out and bought a bolt-on kit for the Pantera, which works perfectly. :>)
Wilwood rotors, at least the cheaper ones (and even the most expensive are still pretty cheap) actually aren't very good at all, I found out. When new, if you look at them hard, they'll warp. Mine warped something wicked with only about 500 miles of use (light use at that), and I had to have them turned. 500 miles later, the car was almost undriveable because they'd warped again! I had all four rotors turned on the car (a brilliant idea, much better than removing them and having them turned on the hub), and since then, they have settled down and are now bloody perfect. :>)