Here's the only concern I'd have about a Rebel--you may not be able to keep up with DH at highway speeds, since it's only a 250 (actually a tiny bit less, I think). Several folks warned me about this when I was shopping, and they weren't all dealers just looking to sell me a bigger bike. But then again, maybe you're not planning on any long, fast rides, so this might be a moot point for you. Just a thought.

Have fun in class!