You should 2 heal. Spirit shell the crushes. Disc priest are amazing. If all DPS excluding tank and healers are at 75-80k deeps your fine. There's not much damage going out really. The disc can pretty much DPS. But I recommend 2 heals! Gl!
---------- Post added 2012-12-04 at 02:43 PM ----------
Forgot to say. We use 2 tanks with 2 healers. Pretty much tanks minimizes dmg don't even have to heal them. Heals just focuses on everyone else really.