You can get there. Start here:
http://www.e90post.com/forums/forumdisplay.php?f=58
Common power-related upgrades for an N54 BMW:
-Tune (BMS JB4, COBB Accessport)
-Catless downpipes (AR Design)
-Dual cone intake (all pretty much the same, BMS makes some)
-Front mount intercooler upgrade (Helix, ETS)
There are also turbo upgrades available for your car which will add a ton of HP, but that upgrade is a couple grand.
And don't forget you'll need decent tires to put that power to use.