I'm a little confused. (How typical)
1) Are you going to be using the main L/R speakers for Stereo music only and never for the TV?
2) Are you only going to be using the built in TV speakers for movies?
3) This wall does not look optimal for a home theater setup. Is there another wall that would be better suited? Either in this room, or another.
Cat Brat; just specifically for music... I agree not optimal for HT. I have a dedicated HT in the basement that I use for games/ movies and such... at the moment all run with Polk audio...(opportunity for future changes!)
If money was no object I would eliminate the nook and make a customised shelving for AV equipment, pics/books etc.; change the mantel to allow for lowering the TV, add the addition of a centre channel. This would enable me to build cabinets for and procure in-cabinet M80s for either side (maybe a foot to either side of the fire place.)
Not sure if I have the relationship capital to undertake that project (not to mention real capital!) so an interim solution is required. Hence the idea of the M22s with sub...At first I thought of the on wall/ in wall but now I am not sure. they would look odd stuck to either side of the mirror. Now I am wondering if the M22 bookshelves with the current stands would be acceptable (run the speaker wire in wall to maximize WAF.