About camera weight and airplanes. I worked for 2 major airlines. The best (safest) climate for flying is cold dry air. Africa is wet and hot. Bad news. The lifting capacity is seriously comprimized, and having spent nearly 20 years looking at aviation safety data, the tropics are dangerous places as far as passenger weight and lifting capacity of the planes.
I traveled at no charge around the world. Whenever vacation allowed. My camera of choice -- a little Minox 35mm with a fold out, bellows Leitz lens. I'd put in my back pocket and be off to Europe. Seriously consider the mirrorless digital. Unless you are being paid as photographer, why turn yourself into a camera porter? Go for the life experience, and remove your ego from the photo expectations. That's my advice.
One of my airlines was FedEx, and so I got shipping for a small service fee. I always FedExed my camera gear to the destination hotel ahead of me. No dragging pounds of gear through airports, dealing with customs and crazy taxi rides with thousands of dollars in camera stuff. Life is too short.