I would either play the mage as main, fire mage + healadin or the pala as main : retrib pala + frost mage (frost to get less aggro and give more survivability).

Actually for some time, I levelled 2 mages and a healadin and it was a very dynamic team. If I had only 1 mage, I might prefer the retrib pala as you don't find aoe places everywhere. Questing and monotarget is still the main road for levelling.