John,
I have almost no problem in FULL Race configuration with the stock rotor and caliper on a 142. Just keep the fluid fresh ( old fluid will boil much faster) and upgrade to a better pad. Hawke makes several that are good race/ street compromises. I run a full race pad that can take 12 hours of brutal wheel to wheel racing and not a bit of fade. The stock rotors last at least 2 seasons of week end racing and the hoses get replaced every other year. Also in these conditions the calipers stay hot so long that the seals dry up and so the calipers are rebuilt every other season, or sooner if the start to leak.
To encourage cooling I have cut the back of the backing plate away to allow more air to get to the the rotors. Just leve the portion that the hoses mount to and carve away the rest. If you run an Air dam or very large spoiler, you may want to run duct to the back of the rotor.
scott