Thinking of a new 5 box PVE setup - could use some input

[TRoN]

druid = no go because of the solar/lunar eclipse stuff and tons of positioning spells and procs.

The druid is a very reliable healer and the healing process can be easily be put inside the global team rotation. You can run all pre-MOP content normal or heroic without focusing on healing at all. Obviously you should have also a Click Heal functionality set for tough fights and messy situations. But overall a Druid Resto is a very powerful multiboxing healer. The problem vs Disc Priest is DPS. The druid dps contribution will be close to null to function the way I've described.

priest (disc) = ranged dps, shields and a HOT and does some basic healing in the group with atonement. Looks like 4 of them can easily heal me through the instances from 15-80.

That 'basic healing with atonement' = ALWAYS full health. 4 priests are overhealing abuse! With a good configuration, your tank will stay 100% shielded all the time and you'll probably run some full instances without a single click heal action. Maybe a POH here and there to bring spirit to the guys