i've had a priest forever as my main healer, shammys are good too with chain heal but i personally prefer the priest over the shammy for the buffs and my priest seems to outlast my shammy's mana pool by far, but the shammy does have reincarnation which is freakin awesome, but i run with a lock too so i use SS all the time but with 3 mages i might trade one our for a lock for their survivability that they add to your group, just having 2 rezzers is gonna suck, cause if you run a instance and your tank is killed that is one rezzer, and the mobs will go straight for the healer and there goes the second. and wipes are no good