The room I am using is shown in the image. Now I am not real sure what specific questions to ask here, but I am worried that given the odd shape of the room that my chosen placement will end up causing acoustical issues. To the right of the listening position you have a big opening into the dining room and to the left you have two tall windows. Behind the listening position you have an even bigger opening into the entry way, which has a tile floor. The ceiling of the listening and dining room is nine feet. While the ceiling of the entry way is around twenty feet.
I guess I would like to know if the layout I have chosen is acceptable, or would I be creating a situation where there are unsolvable acoustical issues? To me it feels like this placement would cause the left side to overpower the right because of the opening on the right side. However, I cannot think of any other placement in this room that could solve that issue.
The only other configuration I can think of would be to put the couch along the window wall, and the TV on the ~6.5' wall opposite. But there wouldn't be enough room that way to center the TV along the wall, and you'd end up with your left channel a good distance farther away than your right, basically trading one set of problems for another.
Honestly, though, I wouldn't worry too much about the left channel overpowering the right. Your AVR ought to be able to correct the levels so what arrives at your primary listening position is the same level from the left and the right. In my own room, my speakers are not symmetrically placed due to a closet door in an unfortunate location; but my AVR corrects their levels and distances well enough. Besides, worrying will only serve to diminish your enjoyment of your system.
I think the best you can do is to look for speakers with an off-axis response as close to their on-axis response as possible. That way reflections from the windows, etc, won't be a different timbre from the direct radiation. Also, plan to devote a big chunk of your budget to subwoofage. With over 7500 contiguous cubic feet to pressurize you'll need a grown up sub for satisfactory LFE -- a Hsu VTF-15H MK2 or two, maybe.
Also, if you clap your hands in that room and the decay of the clap takes longer than a half second or so, then consider getting some acoustic panels from Acoustimac or GIK Acoustics or similar. I'm sure either company could make recommendations based on your drawing.
