If you have a 330 and don't put the M3 bumper on, it's no big deal. The M-Tech isn't a total rip off of the M3 look, it's just sorta similar. It's the one on the ZHP cars. You car is fast enough to warrant a more aggressive front bumper than the stock one. My car is a different story.
I just noticed you said the 2004 coupe bumper. Well, it generally has a similar shape to the M-Tech one so I think you should just go that route.