Over the years club members have successfully used the following bike trip organizers for trips all over the world:
The non-profits offer tours which closely resemble the way we organize rides, e.g. more reliance on yourself vs. having a real-time SAG. The for-profits back you up continuously and, because costs are higher, charge more. They all do a fairly good job of food and route planning.
In any case, when doing these remote rides consider purchasing insurance, especially emergency medical protection when doing international trips.