Cecco
Have you considered tanking the aircraft? I would think you would easily be able to substatially increase the range from your current 700nm allowing for easier routing.
I have flown both the east and west routes and I would choose the eastern route if I was you. Routing as far as Nairobi is easy and once you are past Luxor there is no problem. Its the bit in between thats tough. If you can tank to fly the 1300nm leg then there is no better solution. If not take Kartoum.