You said "mount". The best mount is the NMO. You will need the proper "bracket" to mount the mount to. Both the NMO and UHF mounts require a 3/4" hole.
As for brackets, every bracket for a Jeep is a compromise (unless you have a Cherokee, then just drill a hole in the roof and mount a Wilson 1000 up there!). My favorite bracket for a Jeep is the Teraflex. Get one for BOTH sides! Mount your CB on one side and your VHF/UHF on the other. You WILL have to have the hole enlarged to 3/4" to accommodate the VHF antenna. Also, because the bracket is thicker than your standard sheet metal, you will be better off with the UHF mount.