Having trouble choosing my next Char for BG2... (also first time Ascension)

Sorcerer or Fighter/Mage(or /Illusionist) multi or a dualled (and keepered) Fighter9->Illusionist
(With SCS, Ascension, Refinements and Rogue Rebalancing)

for the following party:

Nalia: Skald (if fighter/mage) or Bard (if Sorcerer)
Jaheira: Fighter7->Avenger
Imoen: Thief6->Invoker
Mazzy: Archer or Fighter/Cleric (still undecided... do I need a cleric due to Ascension?)
Sarevok: Blackguard or Berserker (also still undecided)

All via EEKeeper
Have been skipping cleric often enough to know how to handle battles without one, but considering their buffs and the far higher difficulty with Ascension+SCS, I am not sure I wouldn't need one...

Any help with my decision(s) is much appreciated ^^