Your camera support system should be chosen based on what type of safari vehicle you will be in. There are many options at all prices but I prefer a monopod with a nice ball mount head. I also keep a clamp system handy for when I need to lock in place.
My choice for a really easy and adaptable camera support system for use on a safari is a monopod. For my safaris in South Africa it is the best solution for supporting the camera due to its flexibility, lightweight, and versatility.