I'm just getting into the cheese making thing myself. We've made chevre, and queso blanco mostly. I'd like to get into mozzarella making, since its not super difficult, and its my favorite type of young cheese. I took a cheese making class recently, and it was a good time. We used only vegetable rennet in the class, and the teacher said that many cheesemakers actually prefer it for its cheese-making properties, in addition to its more animal-friendly nature.
peace,
sam