I will most likely use the DK with a mix group for myself, I am thinking I will level it with a Druid, lock, lock, shaman. So I got hots and chain heals with that set up.

If I where to duo it, maybe a balance non boomking druid so it can heal and dps with no issues, and hot up the DK as well as with the DK spells he can heal himself for the most part.