I can appreciate your situation. At least you got them moved away from CB and into something that opens them up to higher quality radios and more manageable antennas. There should be quite a bit of NMO base, no ground plane 1/2 wave and collinear antennas on the market with a much more manageable height that one could mount on the fender on a Jeep and just forget about.I have CB and GMRS in both Jeeps and the tow rig at this point. Trying to move my wheeling group away from CB as much as possible and GMRS has been a good way to do that. I still planning on getting my Ham license eventually, but only one guy in my group has his, and nobody else really wants to get theirs. For me, it all depends on who you're wheeling/travelling with and what they have.
There is a Jeep club near me that another ham and I convinced to switch from CB to GMRS. The other guy (due to his profession) actually has the programming cables and licensed software to program Land Mobile Part 90 Kenwood and Motorola radios which can be had for pretty good prices used. That helped A LOT with the transition.
Sent by electrons or some crap like that.