The room doesn't look too narrow - my old house had a living room that was 11'x19', and we had the system set up in there pretty successfully. I'm going to be a troublemaker and answer a question with more questions, though.
Do you have any dimensions on the room as it is now? How much seating do you need? How sensitive is your display to ambient light, and are you amenable to some window treatment that could provide ambient light control during the day?