Thanks for all of the replies, good information. I did find two with hardtops, the way auto-trader lists vehicles isn't correct; some have max-tow package and trailer-tow.
I will ask for the window stickers.
I agree, gladiator already has a roll cage built over the cab, the one in question should not be labeled as a roll bar.
The one for the Comanche was a roll bar bolted down to the frame and fender well and strong enough to prevent the roof from caving in!
I am an old guy also, there is a video of installing the mopar brake controller in a JT, anyway he removes the cig lighter and unplugs the wires and leaves it in. It looks like the brake controller has its own wire pigtail, you could plug the 12V lighter back in then the Garmin and leave it...