Arcane is definitely a lot more dps. If you can set up the /click macro for 4 AB and then Arcane Missle (missle barrage) it should work nicely. Frost is tough to beat for 1 button spam though. Fortunatly they both gear the same way (spell power and haste - crit and haste are worth about 1/2 of that).

I'd avoid FIre or Frostfire though. they are just too dependant on catching the pryoblast proc's. I have a hell of a time doing that correctly when solo, I can't imagine tying to do it when multiboxing.