Rusty, welcome. The QS surrounds in particular have a much wider pattern of sound dispersion than standard bookshelf speakers and this is an advantage for most of the material which is played in the surround channels. This is especially important when the surrounds are relatively close to the listener(as will be your setup)and there's not much room for the sound from regular direct radiating bookshelf speakers to spread out.
As you describe your room, five feet up on the back wall about two feet behind you should be about ideal. If you can spread them wider than three feet from you do so, because even when they're mounted on the back wall, surround speakers in a 5.1 setup are still side surrounds and play the material from those channels, not the back surround channels. They should be spread as widely as possible. They should point directly forward, not at the listening position.
