this statement confused me:
That receiver should work fine, but I would wait until you get a few other opinions from current owners. Historically, Onkyo has not had a great track record with the m80 4ohm design and gets mixed reviews. Later models seem to do better
I believe the receiver I purchased is a newer model:
TXSR876
Some of the lower line Onkyos shut down under the higher current demand of the 4 Ohm M80s. There are a couple of people here who have used a 7 or 8 series Onkyo with the M80s with no issues.