I realize I'm a little late in the game for this but what are your thoughts about ssb, side band on cb?
As a former CB'er that worked SSB with a "less than legal" amplifier, it is an alternative, although not as reliable as other communication sources.
SSB relies again on line of sight, elevation, power increases, and atmospheric conditions for optimal performance.
That's a lot of ducks to put in a row for communications IMO, especially when mobile. (in my opinion).