Best Healer for Multiboxers?

[Sam DeathWalker]

With the new scroll of resurection Im not locked into shaman healing so I am looking at other classes, as well as the talent trees for MoP.

The three classes are

Holy Priest
Holy Pal
Retro Shaman

PvP is more important to me then PvE. I have to heal a lot of mages taking a lot of aoe damage. Ill have like 5 healers and maybe 15 mages to heal.
Priest has circle of healing which is instant cast, important to keep on the move out of aoe during pvp.
Pal has instant light of dawn and 2.5 sec holy radiance (looking a MoP talents). Light of Dawn is powerful but requires facing.
Shaman has CH but CH is also a 2.5 sec cast. And Healing Rain but targeting is also a lot of extra problem.

Shaman has the best buffs though in riptide and earth shield, stacking riptide on the lead tank will make him invincible basically.
Pal has Blessings and Auras.
Priest has fear ward.

Anti Fear/Silence/ act’s is also important. Shaman has grounding and tremor totems, Priest has fear ward and dispel magic (targeted though), Pal has devotion aura, hand of freedom, sacred cleansing.

And some offensive utility. Pal has blinding light, Shaman bloodlust (but mages have time warp) and fire elemental and hex. Priest has physic scream.

A possible combo might be 2 pals (plus one pal tank) to cover most blessings and auras and 3 shaman. Or other combos as well.

What you think?