Yeah, I'd agree with Tony and say you want hardware raid if you're going to do it right. Speed probably won't be too much of a factor for you, so you could probably get away with something cheap. You probably should still keep some sort of backups, however, as raid isn't a panacea, and if your raid controller crashes hard enough you can loose all your data. Then again, you could consider your CDs the backup in that unlikely turn of events.

Matthew