as far as RACES go, there's only two options for me

five night elves (with Shadowmeld for PvP)
one draenei and four dwarves

because if not all are night elves, the others who do not have Shadowmeld are targers in PvP when others simply fade away

four dwarves because of Gun Specialization and one draenei for Heroic presence (1% increased chance to hit on all)

discuss this and other things.