IMO just RAF up a set of each. You should have a pretty good idea of what each class is like by then. Shaman and Druids are both very versatile, and I'd say Druids are a bit more complicated in regards to healing (changing forms, etc, but throw on some HoTs and you are good to go for a while) Druids can be more mobile with forms, while Shamans have to spec into improved ghost wolf. Shaman are either DPS or heal, while Druids can also tank, if you so desire.