Macs are, hands down, the best system for any type of audio or visual production. The only reason I don't own one is I value the software I enjoy over the boost in speed and flexibility of the system. What's the point of having a computer that can handle everything three times better if you don't have the software to begin with?
No, there's no FruityLoops for Mac. But why do you have to upgrade to Vista?
If you look at the theory behind how systems work and how Vista is trying to protect against piracy, I'm sure there are tons of ways to get around this "MP3" error. It might even be that the sound drivers aren't compatible with certain common playing programs, such as WinAMP or FruityLoops.
Instead of spending your money on a PC with a preloaded HDD of Vista, just buy the barebones, save your money, and probably get extra power out of it.
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