What iksar class to go with iksar shaman+necro?
 

The obvious answer would be Monk to go with Shaman+Necro, but I already have a Human Monk. Is the AC and regen really that much of a difference to go through all the levels again. So I guess my question is if I decide not to go with Monk, what class would be best out of the remaining choices of Warrior, SK, Necro or Shaman?

Monk + shaman is considered power duo, but bringing in a necro alleviates some of the requirement for either class to fulfil multiple roles. Warrior over SK in this setup for two reasons:

Defensive disc
SK and necro DoT spells won't stack

SK would still have better snap aggro, but your trio would have two casters that can innately root to help with aggro management.

I'd go monk. if not monk, I'd go Warrior.

Go Bard and get Iskar illusion mask IMO. Health/Mana song would make Shaman and Necro power houses. Can feed the Shaman life and mana endlessly

Leveling a bard now to make SHM and NEC friends.