Josey, welcome. The M80s are superb speakers, but there doesn't seem to be a compelling reason to use them as surrounds. The QS8s are specifically designed to provide very widely dispersed surround sound and probably nothing else available does it as well. Use the M80s and QS8s for what each of them is designed to do and is best at. So, your first list would be my choice. I'd also consider using a vertical M22 or M2 as the center speaker if you have room to place it, for the very wide and smooth horizontal dispersion that it would provide.
