Do your homework before you dive into cams. They're hollow and bend easily (ruining them). Requires BMW special tools, although I think there may be a special procedure that allows it to be done without the expensive tools. You can swap the vanos without messing up the timing... but not the cams. Getting the timing right on the cams/vanos requires, you guessed it, another special BMW tool. Having done cams on another car is a definite plus, just make sure you really know what you're doing before tackling the cams on your BMW. I've seen a few professionals get it wrong. You might also talk to Stuart (330i ZHP) as he's done cams recently for his TS3 build. Good luck!
04 IR 330i ZHP | ESS TS2+ SC | MagnaFlow "headers" | KMS 3.64 LSD | AST 4100 550/650| APEX ARC-8 18x9 | H&R front sway bar | Vorshlag camber plates, RTAB limiters | TMS subframe & swaybar reinforcements | UUC SSK & DSSR | UUC TM & TME | BW motor mounts | Dinan strut & shock tower bars | vaio 4-bolt oil pump