We're busy doing the same route and, after 6 months, are in Tunisia, waiting to get through Libya. We took the route through Morocco, Mauritania, Senegal, Mali, Niger, Algeria. I believe that the route through Chad into Sudan is impossible, which is why we had to come all the way back to the Med to cross to Egypt and then head south to Cape Town. We're planning to get to CT by Christmas, so the next 6 months may be a bit rushed. Algeria is definitely worth seeing. You have to have a guide, but if you choose the right one, it'll enhance the trip.