late reply... but i just came across this... i would think the brembos with the 6 piston config should do a better job.. but you'd probably need to do something about the power assist for the brakes to avoid too much brake pedal travel when braking.. brembo is also a more knowledgable company in the sense that they have more experience with brakes... which is one of the reasons they're used by so many car manufacturers.. including ferrari with their enzo..

 

from my researching on brakes, all i've been told about 6 piston to 4 piston is that there is not much difference. And thats coming from racing mechanics and brake experts from articles i've read in magazines. Its really your choice in what brand you want. I've heard that stoptech has a great set-up so I would recommend them, but if you like the brembos than by all means get thoughs. Another thing about rotors is if you are at the track all the time get slotted only. They say that for racing slotted is a lot better because of its durability over cross-drilled.