I'm not really sure what you're trying to ask here. From what I gather, you're trying to make a lvl 70 twink? If so, for aoe and healing, I think you're best bet would be a Blood Death Knight. Mage's Seem to be the best for Aoe damage, although I hear Shamans are nice for aoe plus they can heal. Dk's are also the best "farmers" since they do high damage and have high passive healing abilities. GL.
I think you mean an alt, right? If you're bringing it to 90, then here's my advice.
I'd suggest Monk. Great movement for running those boring long distances in the dungeons/raids, great for soloing old content
(especially the tank spec Brewmaster, but even the healing spec Mistweaver works).
For run speed you would have Roll, and you can enhance it further with talents or get Tiger's Lust.
You'd also have Flying Serpent Kick as the dps, Windwalker.
The AoE is really simple with Spinning Crane Kick learned at level 46 (compare that to your Priest, who didn't get Mind Sear until 76!).
It does great damage and has an, in my opinion, great animation.
You'd also get a great looking cleave; Storm, Earth and Fire.
Some passive healing as Windwalker comes from the level 30 talents, and you'd also have Expel Harm,
a 15 second cooldown that heals you and deals some damage to a nearby enemy.
On top of this, as a Brewmaster you'll be able to solo lots of harder old raids.
I think they're comming close to competing with Death Knights as the top solo class now!
They'll summon healing orbs around them for some extra self heals as well.
An added bonus is that you can use the same gear for both the DPS spec and the tank spec.