Hi Captain,
At least with the B&K you'll be getting a very robust amplifier section with lots of power, more than most AV receivers supply, and it will easily drive the 4-ohm M80s. B&K is among the brands of AV receivers (also including Denon, NAD, H/K, Outlaw Audio) that have never had a problem driving 4-ohm loads.
JohnK's comments notwithstanding, I always applaud buying lots of power output. Some orchestral peaks with a few classical CDs I own are 30 dB louder than the pianissimo sections, and you certainly want a reservoir of watts to handle those cleanly.
B&K gear, like McIntosh stuff, has always been expensive--you should check to make sure they are still in business, for parts availability.
Regards,
Alan
