Welcome to the forum!

Either receiver would work great with the M3's. If you watch a lot of movies I would recommend going a step up with the EP350. The QS8's are on of the most loved speakers around here but you could even get away with using the QS4's in a room your size.

Are you going to be using any sort of centre channel for your setup?

Cheers!

I’m armed and I’m drinking. You don’t want to listen to advice from me, amigo.

-Max Payne