A J&M unit is the best way to go. Vic had a version of it (same thing just with a victory logo) and I have that one on my bike. I found it on eBay last year. Buying new is pricey with the cables and antenna you need.
Don't waste your money on a motorcycle made CB as you will be sorely disappointed. Had the J&M on both my TC & Kingpin, then the factory CB on my Vision. Never worked more than a 1/4 mile with any of them and I even replaced the antenna's with Firesticks & tuned them. Problem is there is no ground plane for them to reflect correctly and they don't have any power when transmitting because of it.
Best CB i've seen on a bike was when we were escorted by a group of old retired geezers on Honda Silverwings giving us a tour of all the backroads in southern Illinois. They fabbed up a real CB on the handlebar standoffs and mounted a ground plane antenna on a flat piece of aluminum mounted to the tailpiece behind the passenger seat. They rigged up their own PTT switch on the handlebar with boom mics zip tied to their helmets. They came booming in saying "on your right is the entrance to the Garden of the Gods where the gulf of mexico once lapped up on the rocks over there." When we tried to talk back to them or amongst ourselves, it was 10-9, 10-9, 10-9?