Well, BBKs cost a fortune and stock-sized aftermarket rotors, SS lines, pads and fluid are relatively cheap. Considering the size of 335 brakes I could be wrong but I don't see a need to go bigger, plus if you run 17" wheels it might not be an option.
2011 335i - New toy
2010 Chevy Equinox - Beater
1972 Cutlass - turbo LS project underway