It really depends on your goals and the effort you want to invest in.

For one-class group I recommend shamans, as they are still best group class.
5 druids are great too, but they lack fear protection if you plan to PvP lot.
Both these setups allow the leaderless setup, which is nice for PvP.
With 5 shamans you will miss the tanking role in PvE really. So taking one protection paladin as main would be nice addition and you can boost with him later.
Also replacing one of these shamans with lock can be nice for PvE. You get summons!!!, 13% dps buff, 5% more crit on bosses, soulstone, healthstones, AoE, pet...