Late to this party, but thought I would chime in. Go with whatever folks around you are running. GMRS is a great choice for trail coms. Its clearer than CB and easier to use than Ham, and getting licensed is fishing license easy.
I run a Wouxon 1000G GMRS radio in the Bronco. I chose it because of the remote mounting face plate so I could put the radio chassis up under the dash and the faceplate up out of the way. Its out of the way, a nice set up and plenty powerful. Here is my install thread-
https://thebronconation.com/trail-communication-n.148/kg-1000g-install-t.17107/
Two drawbacks here- first there is no dimming setting on the radio, so when you driving at night with it on, its hard on the night vision. I got some dimming film and cut it out for the display to make it more managable. Second, while this has two speakers in the chassis and one on the mic, it can be hard to hear when running fast in the Bronco. I could solve this problem with an external speaker nearer to my ears, but haven't done that yet.
However, I am preparing to install a dual- band ham radio and it will probably take this location. I will probably go back to the Radioddity DB-25G GMRS I ran for a while but put it on the dash rail.
https://www.radioddity.com/collections/consumer-radios-frs-gmrs-radios/products/radioddity-db25g Its a pain to get this radio set up, but once you do, I like the functionality. Its 25 watts or thereabouts and really loud, so I think it will be easier to hear on the dash. Its a quad monitor too, so I guess if you really needed to listen to four conversations at once, you could do it. I generally turn it back to two, because that's about all I can process at once.
@JoergH is right about the line of site with GMRS- terrain will always beat power rating. Yeah, under the right circumstances on a flat plane or from mountain top, more power means more distance, but I generally dont do a lot of off roading in the middle of perfectly flat planes. I think anything about 15-20 watts is more than enough in a mobile setup.
What does make a big difference is antenna selection and placement. I messed around with this a lot, and got the best results with a midland ghost antenna on the Mountains 2 Metal mount by the A pillar. I would not have guessed this at all because, its a relatively low location and a lot of folks have not had good luck with the ghost antenna. It was the one that performed the best, and I cant really argue with that. Be prepared to play around with it and go with what works best. Also- remember this is for trail coms, not bouncing a ham radio signal off the moon. Good enough is good enough.
One note on the Handhelds- They are convenient as heck to hand to folks, so I generally carry a couple cheapies around with me for spotters, folks in the party who didn't bring one etc. The midland ones are fine, but you can get some cheap ones like the radioddity GM-30
https://www.radioddity.com/collections/consumer-radios-frs-gmrs-radios/products/radioddity-gm-30 for like $30. At that price, it's not a total tragedy if it gets dropped in a creek or runover on the trail.
2023 Wildtrak. "Sometimes you got to get lost, to get found" -J Bronco