Jeeze, the mac gaming scene IS NOT THAT BAD! Heh. The general opinion seems to be that we have none. Untrue. Cruise
here for a decent idea of how it looks.
Basically, almost any 3rd party USB mouse will work on macs, either straight out of the box or using 3rd party apps. Anything by Logitech works well, too. The quality of other applications is way up there as well, using it for school would be fine. The powerbooks tend to be a more professional option, iBooks are better for people new to the scene, but it's not that much of a gap. And generally, it will take you a week at most of normal use to get used to the MacOS. That's partly how they designed it.