http://baer.com/
and here:
http://www.brake-pros.com/pressrel.asp
I have never had an issue with the stock brakes, but I am not in and out of a M5
Bigger wheels and tires, or just more weight on your wheel/tire combo will make your brakes cry on any truck/car.
I get a kick out of the blingers with their stock brakes and 24" wheels.