FWIW, the ride will be much less harsh if you ditch the runflats. That made a HUGE difference even on the stock suspension.
2007 335xi 6AT | Cobb Stage1+ | BMS DCI | VRSF 7" IC | FA 500 400#F/600#R | ARC8 17x9 et30 | RE-11a 255/40/17
"Dude your retarded. It's 6x 6466's they hit full boost at 15k and they weigh enough to get the stance right"