Dude, no worries.. Put the t/v on the full short wall, right where you have the larger bookcase now.. Plenty of room on either side for speaker placement..
Surrounds on the sides, up high.. Just back from the sliding window, about where that little wall hanging is, and same of the other side, just back from that picture.. I guess that would be about 8 to 10 feet ?
And the rear (6th) would go on that portion of the rear wall
that divides the room from the kitchen.. Q's would work wonders in that room..
Place your main seating about 6 to 8 from t/v.. This leaves the room open just behind that seating, giving you (your wife) a place to put a small table, room divider or whatever.. Maybe that larger book case? (I would recommend a folding screen type room divider, with a plant or two near by.. Gives you the opportunity to make changes without a lot of hassle).. All of this breaks up the room, giving you a small area to "mingle with the guests", prior to the begining of the movie..
Don't worry about that slider either.. Nothing is perfect, and it will cause some glare problems during the day, but you can work that out with new heavier drapes, etc.. Easy stuff.. Wife will love the chance to redecorate, eh :-)
One last thing, I would 'hang' those main speakers.. Use the tried and true swag lamp hooks.. Two of those, drywall toggles or stud screws, will hold up a horse.. And don't sweat the small holes you need to put in the top edge of the speakers.. Use small closed eye bolt, drill two small pilot holes in the top edge, one on each side, about one third from the back side to front. This allows the speaker to tilt forward a bit right from the start.. I used to place the hole at the halfway mark, but this just made it more difficult to get the desired down angle.. The forward tilt can then be increased or lessened with the addition of a 3rd eye bolt in the lower part of the back of the speaker, if needed.. I have always used swag lamp chain, and there is a lot of styles to pick from, but the rear lead can also be made from any handy wire you have left over.. No one can see it behind the speaker, so no big deal..
Run that flat 'paint over it' type speaker wire up the wall, or, fish your spkr wire up thru the dry wall, coming out just behind each spkr..
Believe me, you will love the sound.. And, it opens up more of the room on either side of the t/v, giving you space for plants, stereo gear, etc.. Much more professional looking, and your wife will love it for it's "Neatness" factor..
Well, that's my two bits worth.. Hope it helps..
