The place I got my antanna also sold sat. dishes, TV antannas and cell phones. Look in the phone book under CB radios.
I don't know about where you are but the Radio Shacks around here (Michigan) stopped selling CB's last year.
I have notice that the really fancy one's don't seem to hold up in a 4x4. The people I know that have them, they don't seem to work 1/2 the time. So I would say just get a cheap one.