I don't have 350HP or the weight of AWD so big brakes aren't a need for me.

I have stock hp (240), stock calipers, stock bushings, stock rotors, track pads, good/fresh ATE200 fluid, a SS lines. That's really all you need on BMW's until you start adding 100+hp.

If you're fading your brakes after a couple of laps, you need to change to a track only pad and/or add some ducting. Might want to make sure you aren't using the brakes for too long (riding them). Heat is produced more from time on the pedal and less from amount of force applied.