What I use in my open top rok ready CJ-5 is a puney $39.95 P.O.S. Radio Shack TRC-45 (something like that) It's survived many rain storms, dust, mud, beer! Only complaint I have about the radio is the dispaly. It cant be seen easily with direct sun light on it.
It's small, compact, 40 ch, measely 4 watts out, does just fine for trail use. Not to concerned about hwy use, wouldnt be able to hear itover the road noise!. No bells & whistles on it, less to mess with! I didn't want to put an expensive radio in my Jeep for the express reason, I figured what ever radio I mounted wouldnt last long and at $39.95, it's pretty much a throw-a-way radio if it did get mucked up. I do have a HAM radio installed also, it's Mil. Spec rated, so I'm not worried about it and the elements.
Later....
Troy