You may find that Egypt requires airways flight or at least flight under airways at extraordinary minimum altitudes (FL110 rings a bell) for transit flights. Is VFR permitted at all in Egyptian airspace?
This was the case some years ago if memory serves.
I also don't think you'll be able (allowed) to fly VFR between any of the countries mentioned so airways, or beneath them will be the ony way so VFR charts become a bit redundant.
If you really do want to see what's down there try Stanfords in London for ONC/TPC/JOG(AIR) charts which should be available or orderable for all that route.
There is another thread running right now about AVGAS on that route, and the search function will reveal several previous ones. This isn't a trip to undertake without a great deal of planning and preferably advice from someone who has done it before.
You'll be outside VHF coverage for large parts of those routes. I'd consider HF essential. (at that altitude on the 4-5 hr leg Addis - Nairobi you'll be out of VHF coverage for 3-4 hrs...minimum)