Scaleburner, for reliable comms CB is more of a 10 mile solution. Yes, there are exceptions to this under exceptional circumstances, but in reality 10 miles is a good working number. "The 100 Mile Solution" is a common question and probably deserves a thread of its own, but to give you a short answer, it's near-vertical incidence skywave (NVIS) on 80 and 40 meters. You can read more about it
here at Wikipedia. The gear you'll need to do it is (1) a long, low wire antenna, (2) a transceiver that can put out at least 20 watts, and (3) a General ham license to legally use it. And of course a way to power that radio. Call it $500 and some DIY on each end, more if you're buying new gear.
Dragging this thread back on topic, CB's not such a bad band around here. There's so little use that an open channel is pretty easy to find. I keep a Cobra 148GTL around for kicks, and have a couple of Midland 75-785 handhelds to loan to Truly Unprepared friends following hurricanes. It's easier than biking over to check on them each evening, which was what I was doing a lot of after Katrina. Under $40, the 75-875 is a complete package and is so simple to operate that in
actual testing even a social worker can do it.
For an antenna I've got a Solarcon A99 on a 21' fence top rail. In testing it easily hits those handhelds 3 miles away. It does double duty on 17, 15, 12, 10, and part of 6 meters; that's a nice bonus.