BarbB, I'm not sure of the cost differential, but if cost is not a significant factor, or it may be pocket change compared to the total cost of your trip, but I'd opt for the extra body, as it would serve two different purposes--a back up in case the prime camera gets damaged (it does happen).

I've never been on one of those safaris, but can you hand hold a 400mm with a 1.4 converter (almost 640 mm equivalent, not to mention the f/stop loss) steady enough to get the shot not showing any vibrations? Remember both your subject and you may be moving! I may be considerably older than you, but I find my maximum hand held range is now about 300MM; that is not a disparagement of youth, it was great when I had it, but those days are passed . Most of what I've read here on UHH from those who have made similar trips say that even tripods are next to useless (just like on ships and boats) as you will most often be in moving trucks on unfinished roads. .

Enjoy the trip and please post some photos when you return.

I am planning a trip to Namibia, and currently shoot with a canon 5DM4. My longest lens is 70-300L. I was thinking about upgrading to the 100-400L II ( and adding a 1.4 extender) and then I thought about getting a second ( back up ) camera body, maybe the Canon 7DM2 instead. That, with it’s crop factor, would give me almost the same reach as the 100-400 with a 1.4 teleconverter. I could then have a camera with a landscape lens, and one with “wildlife” lens mounted. So, here is the question..How many of you travel with a back up camera, and is it the same model or type as your primary, or would you travel with one camera and a longer reach lens? Any advice would be appreciated. I am trying to make a purchasing decision that will serve me well not only this trip, but for future travels as well.