I find for rig to rig/trail use...the hand held CB's that look like walkie talkies, such as the Cobra's, etc...work great.
No tuning, good enough range for a convoy, and you can talk to the entire group. I also have the exact same CB as Michael...and, I have a set of FRS radios I keep in the glove box for newbies who show up incommunicado.
Generally, the FRS work great, and, if you agree on frequency and sub-frequency, etc...they CAN all talk to each other, not just the OTHER one that came in the pack, etc.
Historically, off roaders use CB's...so, its traditional. The FRS radios that advertise a 25 mile range, or a 5 mile range, etc...base that upon optimum conditions, no obstructions, etc...unlikely in wooded mountainous terrain, etc.
So - Really FRS radios WOULD work, but, unless the guys with CB's abandon them...the FRS radio guys would only be able to talk to each other.
Its a bit analogous to the movie rental media wars...one format might be technologically superior, but, without compatibility, its worthless.
Add the ON ROAD, or non-trail range of the CB in real world conditions, and, it beats the FRS most times.
As for the antenna que - you want to avoid coiling the antenna cable...it will typically be 18' long, longer than the route through the jeep...but, if you coil the excess, as you would with an extension cord, etc...it will reduce efficiency.
Tuning the antenna is simply making the length of the cable and antenna as EXACT as possible relative to a multiple of the wave length of the signal.
For example, If its ABOUT a 1/4 wave in length, as opposed to BEING 1/4 wave, it might fry the radio...a fraction of an inch makes a BIG difference.
The Standing Wave Ratio (SWR) tells you how close you are to the right antenna length (Or to a ground plane or coax deficiency, etc...)....too high a ratio essentially means you are wasting power, and a ratio over 4:1 for example is into radio fry time. 1.5:1 is typically about as good as it gets on a field rig...with 2:1 being "close enough to be ok", and 3:1 being indicative of a problem.
As the CB uses a range, the frequencies covered means that a longer antenna within that range is going to maximize one end of the frequencies, and a shorter one will maximize performance at the other end of the frequencies.
Typically, if channel 1 has too high an SWR, the antenna is too short, if channel 40 is too high, the antenna is too tall, etc. You typically want to balance the SWR readings - so that the channel 1 and channel 40 SWR's are the same as each other.
Your performance is BEST with a smaller SWR. 1:1 would be the theoretical objective.
FRS skip all of that...but sacrifice the compatibility with the majority of the off road world.