Never been to a safari (yet, I hope I still have time ), but it seems if you absolutely need to spend on something, you might better spend it on a second Pro body.
I love my 5DIII, but I would not want to take it into super dusty areas nor would I rely completely on it for wildlife and quick shooting.
I think you did forget some info from the start of this post. I have several bodies (see signature below) and I will take the 5diii and the 1dx with me on this trip
I didn't forget, I'm afraid you misunderstood what I meant.
I recommended getting a second fully weather sealed pro body with quicker (not necessarily better) AF drive instead of your 5DIII (or 7D).
Those were my 2 cents.
Faster AF then 5diii, so that's for canon only the 7D or the 1Dx. What would you advice me then to take along?