Hi Todd,
Like others have said, your present plan has you sitting too far away from the speakers for their separation. Also, sitting against the back wall is not great for fidelity. If you can't place as JohnK has suggested, perhaps you can move the couch closer to the center of the room.
With regard to Klipsch, stay away! You will be fatigued very easily with those horns and the imaging, detail and sound-stage will suffer. The reason you localized the Klipsch sub was because it distorted...not because of placement. I have the EP600 and last night, my sister was sitting right next to it in the big cushy chair (see pictures of my set-up on the wall of fame) watching U-571 and she claims she could not localize the LFEs. That's because the sub was not distorting (but my house sure was
).
For your room size, based on my experience and posts from others, you should go with no less than an EP500. I have the M80/VP150/QS8/EP600 system and I can tell you that it has me and others shedding tears of joy every time we listen to it be it movies or music. Good luck.
