Anything you do and buy that's BMW specific will probably be really, REALLY overpriced. NO I mean really overpriced.
Your better off finding a bigger motor. As for force induction on a 323 motor, simply forget it. Anything without a forged crank will pop in no time flat.
If anything do what i plan on doing. Find a bigger motor.
Born in the BG Raised all over. No wonder I'm confused.