With clear line of sight as you claim,you have other possibilities licensed and unlicensed.ubiquiti radios in the 900 band (928) now they have licensed in the 3ghz,less crowded than the 2 or 5.A Barix on each end and you're good to go.Nanostation M5 and 3 ghz will scan the freqs and let you know what would work.Point is,you can find a workable solution...