The only caster spec of monk is the healer spec, but it does decent damage while levelling (once again if you have heirlooms) and a chunk of that damage translates into healing automatically through eminence and later on even more of it through the buff provided by blackout kicking on a healer. I imagine you wouldn't need to do anything other than a normal dps rotation + a self hot every 20 seconds to keep such a team rolling along. I actually just rolled a gnome monk team (x4 not x5) this week so we'll see how that goes. (my prior monk experience was levelling and raiding a solo box before 5.1).