I would mount the QS8s on the side walls a foot or two ahead of the couch. So one will be mounted above the window and one directly across.

I'd trade in the 150 and M22 for a VP160 on-wall and put that under the TV.

Maybe take it an extra step. Make a deal with Axiom to trade in your QS8 for QS10v4 as well when you trade in the 150 and M22.

House of the Rising Sone
Out in the mid or far field
Dedicated mid-woofers are over-rated