Draenei

On further consideration, I think a Draenei hunter would be best. There appear to be at least a few Draenei-only quests, and I don't think there are any that are Alliance-except-Draenei, so there should be slightly more XP available. Plus, Draenei have a slight self-heal, and before I hit level 10 I can be a jewelcrafter and make some healing stone statues that I can bank.