Another point to ponder..... safety....
If you have to carry spare fuel in cans, diesel is far less volatile then petrol.
And if you're stuck without fuel somewhere, you're more likely to get some diesel from a passing truck, then from a passing local in an old banger, however hospitable they may be.

When we decided to take a couple of months a few years back to go to Morocco, we opted to have the V8 that was in our SIII (Dormobile) swaped out for a 200tdi. I have to say this was the single best decision we made on the entire truck. Our average fuel consumption was nearly cut in half and we averaged 27mpg on the entire trip. It was very relaible and did not start missing when hitting large puddles down by Winchester(like the V8). The swap paid for almost half of itself on that one trip.

One thing I would be sure to do is to check the torque on everthing you can and use thread locker where possible. We rattled all kinds of things loose on ours. Oh yes, and a bit of strategic soundproofing can increase your quality of life as well.

Sounds like a great trip.