|Unfortunately machine wise, it does matter. I'm talking more along the lines of your experience and what you are qualified to be flying. In any case, here are a few companies based in Canada that operate for the UN:
- Voyageur Airways (http://www.voyageurairways.com/) operating DHC-7s, DHC-8s and CRJs in Ivory Coast, Sudan, Congo, Chad, Afghanistan.
- TransCapital (http://www.transcapitalair.com/ website has been under construction for many years) operating DHC-7s in Ivory Coast, Liberia, Haiti, Afghanistan.
- Regional 1 (http://www.regional1.ca/) operating DHC-8s in Afghanistan and I don't know where else, in anywhere else.
- DAC (http://www.dacaviation.com/) operating DHC-8s mainly based out of Nairobi, Kenya.
The Red Cross also does a lot of flying around doing humanitarian work, they function much like the UN where they contract out the flying. I believe most of the companies with Red Cross contracts are based in South Africa like Saffair (http://www.safair.co.za/) who operate a large swath of aircraft types (anywhere from King Airs to Hercs) all over the world.
bizjets links are a great start to browse through too. I remember thinking that it seemed so difficult to break the ice when it comes to flying in Africa. I highly highly recommend starting off with a Canadian company that operates overseas until you get a good feel for what's out there. There are many many questionable operators that are based in Africa, and also some really good ones, but the list of operations is extremely long - as I said Africa is a really big place, something a lot of people don't realize.
But you're pretty safe starting with Canadian operators... despite bad things that are said about all of them on Avcanada, in the big picture of things they are very safe operations that treat you well - compared to the trouble you can get into over here in Africa. Once you're here, it's really really easy to start networking since pilots of various companies tend to hang out together, amongst the numerous ex-pat parties.