Healer types work wonderfully as well. I am a conjuror, and I team up with a templar. Pet tanks, cleric heals/nukes/debuffs, and I heal/dot. Not sure about higher lvls, but I don't see why it would stop working :) I'm lvl 30, and he's lvl 27. We can duo white con double ups (to me, as I'm higher lvl than he is). Not sure about a yellow con yet, we'll have to try that one out!
But if you don't like healer classes (you said you wanted something different than mystic...) Then duo-mage... any of the mages can go with conjuror. Just don't get aggro away from pet! Tank I had trouble with, as a conjuror, I can't heal the tank... pally maybe, tho?
---Fyrespring---
50 Provisioner
30 Conjuror