Most solid duo for Kunark and Velious

[Hiragawa]

Shaman/Monk or Shaman/SK. I can see Shammy/Mage being rather good as well, but I'm fairly meh about mages.

Monk: Decent dps (compared to the mage), mend is nice in a pinch, and buffing him up with all the proc spells/regens before a pull means that if something goes wrong, FD is there to stop the pull and prevent your shammy from taking death aggro.

Shadowknight: Pretty much the same. FD is things go wrong, Lifetaps always help out, and I imagine the snare doesn't hurt. Plate armour is a nice bonus.

Shaman: The ultimate 'duo' healer. Haste, Slow, SoW, Proc, Tropor, DoT/DD, Pet (although not even close to a mage's dps from the pet). Not to mention chewing their legs and what not to get mana back :P