I'd guess you'd be fine with the 6 piston Brembos from the Performance Pack. I did just that and the difference between that and the stock is night and day, especially if you track the car, probably not so much if you autocross, and likely even less if you drag. For the rears, you should be fine just stepping up to a slightly more aggressive compound to keep the balance and bias you're used to. That's why people running G-Loc pads go with combos like R12/R10 or R16/R12.