Hi Help class selection and play style

Hi all. Wanted to hear all of you I have decided to dual box 2 characters to 80 from 71 - 72. Now the problem is one of the two has to be a priest . But for the other i have druid, warrior, hunter. So What to choose, i most lean towards druid / Priest because i they would be really cool to have with the duel specs comming. But what do you all think?

And how should i play it? Disc priest? Holy priest ? shadow priest? Feral druid? resto ? balance?


Oh and BTW what fastest? Quest or instance or Aoe grind

Regards

Balance druid and discipline priest?

Or maybe BM hunter and shadow priest?

Can't help with what would be quicker....I've only really multiboxed for RAF boosting.

I am thinking quest would be the quickest for a 2-man operation. Finding groups that can fit both characters isn't always easy nor is convincing the average pug that you can play two characters at once (I don't usually tell them). I would advise doing the instance quests since they're usually double the xp of a normal quest but I wouldn't do instances exclusively.