Now in Tree of Savior only can have 3 class (and base class). No more circles or Rank order. The Basic class of Support and Healer is a Priest and the other class of support are:
-Kabbalist: Great healer and with can duplicate monsters for drops.
-Oracle: Drops changes, shop to change sex and inmunity
-Pardoner: Buff Shop, Magic Defense and Healing Factor
-Plague Doctor: Healing Factor, Cure and Damage
-Dievdirbys: Reduction of CD and SP regeneration
-Chaplain: Auto Attacks Buff and Holy damage
-Krivis: Stats of attack buff (STR and INT), Critical buff and healing
The question is the heal, now have Overhead, is you abuse of heal this need more SP to use, but with Priest, Pardoner, Plague Doctor and Kabbalist the healing factor be Increase and the overhead effect decrease.
If you go be a Full healer, need take class that make the heal overhead decrease and give skill or healing factor buff, but you can take class can buff damage, defences or give inmunity.