If your terrain is pretty flat and line of sight is good, MicroMobile 50 watt would work.  How many times are you needing to talk the full 50 miles?  If that's pushing it a business band would be the best bet.  Either with a repeater would be better.  There are new cellular radios similar to the old Nextel phones that work with cell signal.  Here we can't get a cell signal everywhere and a repeater would have to be at least 300' to get over ridges, mountains would take 1000'.  15 watt MicroMobile is what we use with acceptable results.