Mike, I think you answered your own question when you said:
In reply to:

I REALLY want 7.1!!

.

If you really want it, anything less will give you nagging dissatisfaction.

You should check with Axiom on the FMB and the M2, but I'd be flabbergasted if they designed a bracket that would not work well with their own speakers. I'll bet you'll be better than fine.

Is hires audio similar to Hires Root Beer?

That will be a great system. What are you doing again for the sub?

bibere usque ad hilaritatem