If you are going to be talking rig to rig with little or no distance between, the choices are many. Cb's can be purchased very cheap, but coax and antennas come in to play. The newer FRS & GMRS Walkie talkies are cool, but they have their limitations, including batteries to replace. CB radios mounted in the rig are reliable and take no batteries, but can't be taken out for portable use very easy. Your choice based on your needs.