CB is only really any use for car to car in convoy situation, due its limited range. As for GPS suggest you go to Garmin home site, this list the map coverage available and what units they run on, it depends what you want to spend and what you want it to do for you. Dont forget to take good paper maps as well. As for communication the only real answer is sat phone as this will give you guaranteed communication in emergency situation, not that expensive ,as you only pay what you use , you can even hire one .