Your biggest concern is getting a high tower or building to set up equipment and antennas, that is tamper proof with limited access to authorized people to work on troubles and upgrades.
Two handheld radios will not get much range, Mobiles with some power and good front end selectivity from strong signals out of band is a better idea. The Duplexer is a requirement so you only need one antena and feedline./ This can get rather expensive for a commercial unit and VERY difficult to homebrew even with access to precision machine shop gear.
73.....JD, FISTS #3853,cc 455,SKCC # 1395,tribune #12,
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