A lot of Pal + 4x sham boxers have swapped in a boomkin or a warlock for the 13% damage bonus and it is definately worth it imo. If i was starting from scratch I would go destro lock (mainly for replenishment) but mine are low level and my druids were sitting at 60.

For healer again my preference is sham as eventually it is likely that you will switch to 4xdps and elementals seem to be easier than SPs to get good results though my highest level priest is sitting at 60 so I do not have first hand knowledge.