I want to throw something out here, because everyone's been so helpful here...I just want to "give" a little instead of "taking"!
I don't even own Axioms yet (They're on order)but I think a huge factor here for budget and overall sound will be subwoofer(s). That's a really big room you've got there, and even if you don't normally play your music terribly loud, I'm sure as someone who has experience as a drummer, you DO want to keep lots of dynamic range.
Anyway, I can't help much with an M60 VS. M80 question, or how much power it will take to drive either. But I DO know that if you have a powerful sub or two in there, it'll take a lot of the pressure off eith main speaker!
