I dont think reliable com with 50 mile range is too unrealistic with CB if you do it, its just costly. 70 watts on SSB should work in most places but I woulnt call it 100% reliable, now with a 200 watt amp I would trust it alot better.
2 things that I noticed kill the range of CB are cities and interstate highways. When I lived in BFE, 70 miles from the nearest interstate highway I could always get 5 miles of range on AM, as the band was empty. Once I even talked 12 miles on a old radioshack TRC-211 5channel handheld (mountaintop to valley).
Also, in any TSHTF scenario, those 40 channels will be jammed with traffic, I would strongly suggest radios capable of going out of band for such hypothetical situation.
You can spend a fortune, but your range is only as good as your setup. A good matching antenna with a cheap walmart radio is better than a cheap antenna that the impedance does not match. All this is also kind of useless if the wife becomes annoyed with the occasional foul mouth trucker using your channel and she turns the radio off.
If one of you is in a city, the other is going to need alot more than 70 watts to blast through all the crap and interference that cities for whatever reasons make.
A beam or yagi antenna is a great idea if you know where you are going to be but its so directional its useless if its not pointed in the right direction.`
Some sort of tone paging or tone squelch would be a great idea, unfortunately nobody manufactures such a device, except maybe a 10meter ham rig modified for CB but I really havent looked around much.
I think CB is your best choice for something that can be installed in a vehicle and used without getting out and setting up antennas, tossing ropes in trees,etc. CB is sort of in between HF and VHF, has characteristics of both, it follows the curvature of the earth like HF somewhat, but you can use an antenna small enough to mount on a vehicle and it doesnt have to look like some kinda telsa death ray coily thing like I see used by hams.
Thats my thoughts, good luck with it.
