I have the 19" p40s. The wheels are 9" fronts and 10.5" rears. I am running 265/30 fronts and 305/30 rears with no rubbing issues at all.
I also recommend WheelSTO & IND. I have purchased from both with great results!
'08 E92 M3 :: AW/FR
:: HRE P40s :: Remus Race Exhaust :: RD Sport Rear Bumper