Classes are up to you.
With two in Arena, possibly Ret Paladin, Warrior or Frost DK; any two of those or two of one of those.
You could try 2x Heals in battlegrounds.

Honestly, I'd go 3/4/5 boxing... playing more towards the strength of boxing... the burst to burn things down.
But you can try 2 if you like; nothing says you cannot enjoy two or change to more down the road.

For software, get a trial of IS Boxer.
Or if you're comfortable writing scripts/adapting the examples given, go with HKN.
IS Boxer is a subscription server ..... www.isboxer.com
Hot Key Net is free .... www.hotkeynet.com