Here is a really rough outline of what my room looks like. certainly not to correct ratio but close for an example.
I have the proposed wides at the position I would like them to go and also the rears at a position on a bookshelf.
The fronts are 340's and all the rest are 170's. The surround sides are wall mounted and the rears will be placed on a bookshelf. The wides will be on stands. I also have a spot proposed for another sub. I will be getting matching 12inch subs only for the fact that the 15's will be too large for my area but want something to fill the space on the other side of my AVR stand. Somewhere down the road I will add another set of 170's for 11.2 system. My main listening center is at 9.5ft. From the back of the couch to back wall is 6.5 ft.

What do you guys think? Is sub placement ok? Speakers? Or am I going over the top with another sub? My main listening is movies and shows. My flooring is a deep shag carpet.