I'm new to multi-boxing also, but from what I gather about Keyclone (i'm using AHK atm til i get a few extra bucks to get keyclone) you don't need to have the same classes since all Keyclone does is copy keystrokes(basically).

Right now I have a Priest and a Mage. 2 on my mage is a fireball/frostbolt castsequence while on my priest its Smite.