In reply to:

But I think the M80's need some serious power


Well, the 80s are 4 Ohm, but they don't need serious power by any means. They're actually pretty sensitive!

So you might have more of a concern in getting a tube amp that will hurt the 80s' feelings..... ;(

::::::: No disrespect to Axiom, but my favorite woofer is my yellow lab :::::::