ele sham, mage, paladin could work pretty good.

I highly recommend hybrid classes, since they're the most versatile. So if you want a paladin, personally i'd go for shaman, druid paladin. Since you can do everything you can think of with 3 hybirds.

For casters an elemental shaman adds a lot, boomkin aura + totem of wrath don't stack.

For melee an enhance sham adds a lot, but if i'm correct bloodDK adds most if not all of those buffs aswell.

Don't worry about tanking/healing etc till you reach 80. leveling as 3 dps works fine and probably the fastest aswell.