Do you have access to the 5.1-5.3, or 5.7.-5.8 frequencies in your region? If the SA you show is all that you have access to, then you're going to to have to use a 20 or 10mhz channel width and try to fit into one of those valleys. Is anyone else at this site using Cambium equipment? If so, you might be able to do some GPS sync, and use back to back frequency reuse.