Todd, you have a lot of options to play with. I'd like to further expand on JohnK's suggestion of rotating the whole set-up and move it 180 degrees, placing the main speakers against the longer wall. This way, you won't be blocking the window and you will also be able to get more separation between the left and right channels--something more preferable to your seating distance.
You mention that you thought the sub was overpowering in the Klipsch set-up. I don't think that is a fault of the sub itself, but more of calibration and placement. Do not be afraid of getting too much sub for a room, you can always adjust the volume down. I would much rather have too much sub, than one that is just barely adequate. Trust me on this one. You like action movies and hard rock. A capable sub is a must.
Definitely look into auditioning some systems. I think the M80s or M60s will do you just fine.
