You would not be settling for M60's...

My room is much bigger than yours and my 60's have no problems. Maybe some Yammy owners will chime in here that have tried or own the 80's. There was one person, can't remember his screen name, that his Yammy kept going into protective mode and shutting down. He called Yamaha and they said that particular model would drive 4ohm speakers, but for some reason it would keep shutting down.

Good Luck..

M80s VP180 4xM22ow 4xM3ic EP600 2xEP350
AnthemAVM60 Outlaw7700 EmoA500 Epson5040UB FluanceRT85