Your Opinion, Please

[RobinGBrown]

If you're used to an RP server make sure you move to an RP-PVP server not a normal PVP server. The normal PVP servers are full of asshats with stupid names like 'IPWNU' and the chat channels are non stop smack talk. At least on the RPPVP servers people who gank you aren't called 'Grieftoon'.

I think that group composition doesn't make much difference, go with something you're happy with rather than worrying about wether or not you'll be vulnerable to tactic x at level 80. All classes and races are useful but for multiboxing it's down to how easy you want to make it: 5 of the same class is always going to be easier than a mixed group but a mixed group should give you better synergy overall.

[Ualaa]

DK's start at 55th, and you'll be 57 or so when you leave their area.
That's basically RAF for a team, just by starting them.

You have all the flightpaths for the old world, although you'll need to explore if you care for that achievement.

They're a strong combination to consider.
Not sure if you'll have as much success in arena with 5x anything, as you'll have 4x shammies plus 1x dedicated healer (not you).
But as far as battleground go, or world pvp's.. 5x DK's are intimidating.

I personally prefer shammies or druids, but DK's are a good option.