Popular performance mods for an X5 4.4i ?

[varun]

I am purchasing an X5 4.4, probably an '04 model. Really want a 4.8is but its not worth the additional $10K - $12K which I will have to shell out. My question is what are some simple engine mods that can give me more HP and more torque? I was thinking of an AFE magnum force air intake which will make it sounds sweet and give me +10HP and +15 lft/lbs ? What else would be a good investment out there for power increase? I saw a thread which involved the dinan supercharger (S3 i believe) install from a dealer but I think $17K for that is ridiculous, I would get the cayenne turbo instead! Input is appreciated.