You could go Dreamstate on the druid, which is a hybrid Balance/Resto build.
Deep enough in Resto for Swiftmend, deep enough in Balance for Moonkin.
Extremely mana efficient, but lacking the talent based AoE's of both trees.
As the only healer in a group, this is not a good idea.
With a priest for heals...

Priest is primary healer, has strong AoE heals.
Dreamstate has very good single target dps, which you're doing boxing anyway.
You still have Hurricane on the Druid if you want.

You then have the option to roll HoT's when needed or have a DPS provide fairly significant single target heals.

I absolutely loved dreamstate in burning crusade.