Thanks for the info guys! To clarify, I have the "rear surround" speakers mounted on the two side walls approximately eighteen inches behind the couch and angled towards the center of the couch where my wife and I sit. You can't see them in this picture but they're there. They cannot be moved any further back or they'd be in the kitchen.
My AVR is a Pioneer Elite VSX94TXH
So if I understand correctly, my desire to add the two additional speakers for 7.1 surround would not work. I wanted the LCR speakers on the back wall, the rear surrounds to stay were they are (on the side walls 18 inches or so behind the couch, angled toward the sitting position), and then the additional two speakers for 7.1 to be underneath the window and on the opposite wall where my daughters toys sit. According to the Dolby site, those two additional speakers would be too far forward. I cannot have any speakers behind the couch because the family room is open concept and flows right into the kitchen.
Based on the parameters of the room and the requirements of 7.1, it looks like I am limited to 5.1. Thoughts?