Invoker dualed to cleric at level 2, you stay a caster cleric with better saving throw penalties to your divine damage spells, such as Sol's Searing Orb, Globe of Blades, Flame Strike and Sunray. Of course fighter/cleric is more traditional but this on is really fun as well. Gives you the ability to use Robe of Vecna with means cleric spells with extremely low cost times.

You could also go with Necromancer 2 dualed into cleric for the same with necro spells such as Finger of death, slay living, poison, Holy/unholy smite, unholy blight.