Not im a bma brother, but if u really desprately want it, turbo is the way to go because it has lag under around 2,500 or 3,000rpm depending. Supercharges run on the timing belt there for they dont lag and always run which isnt too good for your engine. You will also have to spend alot of money on new pistons and shafts ect ect to handle the extra boost. But seriously, i think you are better off leaving a bmw engine N/A (naturally Aspired). My opinion but its your car so go ahead.
Michael
