Sorry I should have elaborated more,
We are going on a number of 3 vehicle expeditions over the next 3 years, 2 people per truck so 6 operators, all can apply for licence if needed. I am based in Ireland
Comm's are going to be used for a variety of uses, from 5-10minutes status checks en route to co-ordination while out on trail and for sports (we're avid climbers and kayakers). I would like at least 1 vehicle to have some form of HF for long distance emergency communications in North Africa and parts of Eastern Europe.
Terrain will mostly be forest and mountainous
Being you looking at multi-country radio use its going to get complicated.
First at home, You dont apply for a license. You need to take a test and pass to be issued a license. Communications Regulator. is the Irish license athority, similar to the FCC in the US. Each country is going to have its own license requirements and while some counties have reciprocal license they usually require the home country license to be more than an entry level.
I would suggest contacting the Irish radio society
http://www.irts.ie/cgi/index.cgi and find someone local to help you get a license.
Once you get a license in your home country you will need to find out where and IF you license is usable in other countries. Most EU counties, us, canada, australia allow automatic use of a host country license in there country but the rules change and I dont have specific com req agreements.
Once you get into underdeveloped counties and where leadership changes at the drop of the hat, ham radio is often not available with a special license and often under heavy monitoring by local government.
Ham radio might be an option in some countries and may cause you issues in others. Since each country issues its own license getting a "business band" radio license is pretty much out. FRS/GMRS is a North American license, There is a similar PMR radio in the EU, but not sure how much or if Its legal outside of that. HF could serve you but again, it allow information in and out of a region and some of the more totalitarian African countries may not want that freedom available to you anyone.
If you go the ham radio, figure 100-300 for handhelds, single band on the low side, dual on the high, moble VHF/UHF will run from $150 to $500 single band or quad band. Mobile HF radio setups will run you close to $2000 for amateur radios double that if your forced into a "commercial HF" system. All numbers are $USD.
Again I would suggest getting in touch with both the Irish transmitter society as well as a caravan club that covers your intended travel areas to see what they suggest.