True that they speak french, but I'm pretty sure they have to speak English over the radios. Its not like in Quebec where you can speak either English or French.
I'm not too familiar with Western Africa, only Southern so I can't be of much use. My understanding is that the major companies operating around there are under contract from other states (Example, Kenn Borek [I think its them] operating their twin otters and dash 8's in chad). Or are using planes that are run down and of average maintenance.
But I can tell you know, that with the hiring that is happening, and will continue to happen in Canada, that you will NOT be on the ramp for 3 years. 6months tops if you choose your companies right!