After watching the film about the Tour de Afrique (very cool by the way) I checked out the tour company's website and discovered that you can create your own tour, get people to sign up and they will help with the logistics, etc. Plus, if you get so many people to sign up (and people can sign up from anywhere in the world) you could get to ride free. Can be tours anywhere from 5 days to six months and anywhere in the world.

http://www.tourdafrique.com/dreamtours