In the exact same boat.
My First problem, Sedan or coupe? Coupes are definitely more fun, but sedans with sticks are also fun and maybe a bit more practical.
Second Problem. 330i, or G35? Definetely get more for your money with the Infiniti, but BMW has free maintnence for 50,000 miles. I drove a 2003 330i tonight with the sport package and real leather, asking price $36,800. 2004 Infiniti G35 Sedan, with all options, (spoiler, Navi, BOSE etc.) $36,035. Honestly comparing the G35 sedan with the 330 Sedan, the performance is about equal. The G35 may be a bit faster, but the BMW nearly matches the speed with 35 less HP. The BMW IMO handles a little better and I really like the looks of 330 Sedan better than the G35 sedan, but I can't fathom spending 36,000 for a nearly 2 year old car when I can get a brand new decked out G for the same price.
I am split between the G35 Coupe and BMW330i Sedan. For some reason I really like the 330i Sedan looks and wheels. I don't too much like the 330 coupe, looks almost exactually like the Sedan with 2 less doors. Plus as somonelse stated, there are BMWs everywhere, and they don't really turn heads, unless they are M3s, or the new 6 and 7 series. My only reservation on getting the G35 is that its a Nissan, not to sure of resale value or build quality. i haven't heard too many problems with BMW's except for this girl that had numerous problems.