Plenty of Hilux trucks in Chad, its a very practical and well suited vehicle for the terrain there, and easy enough to repair. It may feel or seem a bit less rugged than a Troopy but those who live there are, of course, smart and practical, they know what works. I would be absolutely comfortable with such a vehicle in West Africa and certainly in Chad and the C.A.R. If I were focusing more on Southern or East Africa, I may prefer a Landrover of some sort, but a Hilux is fine too. LR or Toyota, you are fine in Africa. A small camper is a nice concept for a Hilux and I've seen a couple around in Southern Africa, although is not a combo I have had myself. I would just be careful to ensure it does not become too heavy and overladen at the back, I saw a few with huge water capacity too far to the rear which I didn't like too much. For the distances needed at least to explore northern Chad with a large degree of autonomy, I would be very careful about adding a camper unit. But as this is really pushing range to the extreme, which really isn't necessary anywhere else in Africa, it is probably a good compromise between practicality and comfort.
I'm looking at some alternative ideas now with the lifting roof tent, just as in your profile pic