If your couch is right up against the back wall stay with 5.1. You can still buy a 6.1 or 7.1 receiver but you would be configuring it to 5.1. You won't really be wasting the wattage from the 1 or 2 channels not being used because all the power comes from the power supply anyways. It means you will have more reserve power for 5.1. I have tried 6.1 and 7.1 and I have about 11 feet behind my couch but I found it distracting so I am staying with 5.1. I really tried to convince myself 6.1-7.1 was better but whenever I turned of the center rear surround I liked it better. Alot of people absolutely love it in 6.1-7.1 but there are also some like me who prefer 5.1.