Never healed in Vanilla, help-priest or druid?

Hi all
As tittle said i have never healed in Vanilla, my Vanilla char was mage.
After Vanilla I am a constant healer
Hand of adal with Paladin, LK - priest dic after that till MOP i switched to druid . Have Proven healer in MOP and in WOD ( mop-priest. wod-druid).
I know very good about the classes for heal but about Vanilla i dont have a clue which one to choose
.
i am just stucking between dudu and priest.
Some helps are welcome
Greetings all
As tittle said i have never healed in Vanilla, my Vanilla char was mage.
After Vanilla I am a constant healer

I know very good about the classes for heal but about Vanilla i dont have a clue which one to choose

i am just stucking between dudu and priest.
Some helps are welcome
Greetings all