Be carefull! La Republique Centrafricaine, la Republique Democratique du congo and l'ex-congo Belge are not very safe today. I dont know if your mate is a European or a local, but the local people see the problem a little bit different. In "special" aeras it is better to use cash, and for this countries Euros, no Dollars!!! Money can be helpfull in "special" situation. But the risk is high if you cannot use the service of a big, puissant, local outfitter and a lot of protection.