I'd go shamans too. Druids are a bit more complex, youd have to macro form shifting, etc to make the most out of druids. I think that a well played druid team will do better than a shoddily played shaman team, but overall shamans are a better choice, especially if its your first time boxing. But if you are using RAF, why not level both teams to 30, then gift the other to 60, so you at least have both options.