Sounds like an interesting project, Ben. I'd love to find something to occupy my photographic energies so comprehensively for several years! Good luck with this venture.
Having shot both types of B&W films, I think that the C41's have only two real advantages: C41processing, which means any place that does color neg film can do them for you; and finer "grain" than conventional ISO 400 B&W films. They have lovely tones and are really quite beautiful in their own right, though not the same as Tri-X or Delta 400. (I have never liked the look of color film converted digitally to B&W, but if you do this is a consideration.) Beyond those two advantages, I've not found other compelling reasons to shoot C41 B&W that much. I have a long history with silver based B&W film, and i just love the look so much I don't want to give it up.
Another claimed advantage claimed for C41's is that you can use the scanner's hardware dust and spot removal feature (eg. Digital ICE) with them, which you cannot do with conventional B&W films because the metallic silver grains are treated as dust, costing you image quality. I haven't found this to be that important to me, but if you're shooting a lot of film the ability to use digital ICE could save you some time. I think you'll still have to "spot" the images in Photoshop regardless. I have had equally good results scanning both types with a Nikon LS-8000 film scanner.
I completely agree with you that you MUST process your own conventional B&W film for decent results, while doing your own C41 is optional. You mention that you can't rely on the labs in the project's location, so it sounds like you are going to be processing your own in any case. Given that, I see little advantage to C41's.
How you go about processing the film depends on your intended volume of film shot, the infrastructure at your destination, and whether you'll be on the road all the time, or operate from a fixed base. If you're shooting a low volume of film, staying on the move, or have limited access to electricity or water, then manual daylight tanks (eg Patterson, Nikor, etc) are your best bet. Otherwise, you might consider purchasing a used Jobo or other automated processor. You could do C41 or conventional B&W with equal ease, and do a batch every day or so when you've accumulated a sufficient number of rolls of film. You'd then be free to choose whichever film you need, and be able to economically process either type.
I use a Jobo and get fantastic, consistent results with conventional B&W film, and C41's a no-brainer. being able to press "start" and walk away to do something else while the film spins around is very nice. You could likely sell the processor after the project is done, and suffer only a small loss in depreciation on a used machine. Something to consider.
Maybe a place to start would be to shoot a few rolls of either the Ilford XP2 or Kodak BW400CN and see what you think of the film itself, then go from there.
Keep us posted, eh?