Assisting Sorcs (even just 2) will be very nice.

Bsed on the offensive capabilities of the Shaman, though, I would have to say multiple Shaman would be the 2/3/4/5 box specialty. They also can cast an AE Heal, which can help vs AE, and in doing so will help to build up the Offensive WAAAGH.

Their offensive capabilities are quite strong from range. They also have quite a nifty knockback ability, although it also knocks themselves back (which would not be good for you ).

Other then that, I can't see any other good combos. I suppose Squig Herders or Magus would be good in multiples, but only if they fix the pet pathing and make Magus actually worthwhile to play (I honestly didn't see a single Magus in Preview Weekend, although I didn't spend much time in the Chaos Zones).

Good Luck, look at Sorcs and Shaman.