Steve, as to your room width, the basic idea is that the back surround speakers should be separated at least enough for the usual listening positions to have a speaker both to the left rear and right rear. Once that's satisfied, the same principle as applies to the front speakers should also be applied: separate the back surrounds by about the same amount as your distance from them. For example, if they'd be about 8' behind your listening position, they should also be separated about 8'. In most cases your 14' room width should be plenty for adequate separation.
