I'd go with the Yaesu FT-897D, it can be powered by 120 AC, an internal battery pack or 13.8DC, it covers HF/6/2/440. Not cheap at about $950.00 new, but it is very versital, 100 watts powered, 40 watts on the battery pack. A antenna tuner is available also.
Read the book "Patriots" by James Rawles. It has a lot of info on radios and different situations, a great survival read, lots of good tips. A must read.
They also used 500MW radios as there were forces looking for them and high power allowed them to be easily found with DF equipment. I'd include some Trisquare/GMRS for close range coms, from Mt top to MT top, you can transmit 50 to 90 miles. Lots of Sanyo ELOOP AA rechargable batteries and solar chargers for them.
You are going to want to have a varietty of equipment, the Yaesu, a 2m/440/CB W sideband/GMRS/Shortwave receiver/good scanner and PV panels, batteries, antennas, antenna wire.
It would not be cheap, but you would want to have as many ways to monitor as well as talk to. In many cases, monitoring will be the most important. In the book, the even used military wired telephones to talk to the spotters in their camp. Buy the book, it will give you many ideas on radio equipment as well as many tactical things, any one looking at survival should read this book.
If cashed, waterproof containers made to be EMP proof, don't forget to insolate the inside of the boxes so the equipment does not rest against the metal container.
The only equipment that costs a lot is the HF radio and a good scanner, but you would not really need trunked type receiving scanner, I think all of that will be down, FM, sideband and AM is what you would most likely find. If you cannot afford a HF transceiver, get a Shortwave receiver, even if you can't talk, you can listen, a Sony 7600 receiver is small, gets all shortwave bands, has sideband so you can listen to Hams on HF and uses 4 AA batteries, a great compact unit, I'd get the other radios for sure, maybe a HF tube transceiver bought on the cheap if the Yeasu was out of your price range.
Extra coax, fittings, lots of open wire, extra radio batteries and 12V chargers for everything, 12 volt cords and a 12 V soldering iron and solder, lots of tape, the list goes on. Try to find others in your group who will buy some of the equipment so it's not all on you.
Really think this one out. There will be many situations where you won't want to be found, the Trisquare is a cheap radio that would work well against all but the best DF equipment, great for short range coms.Get some low power transmitters for sure, second best would be GMRS, but it can be heard by others, that's why I like the Trisquare for short range coms.
My Best, John K