Hi Jan,
I took binoculars woith me when I went and to be honest they were the best thing I did take, I have a good camera and took some excellent pictures, but the binoculars gave you that edge when scanning the horizen, while watching elephants at a water hole, I looked beyond them to see vultures and a hyena feeding on a dead zebra, something those with cameras couldn't see (unless they had terrific zoom), so my advice would be yes take some binoculars with you, I paid about £100 for mine off ebay, but they are available from camera shops, they are Nikon Action 10-22x50 CF (wouldn't call them lightweight, but not too heavy).
Have a great trip, its fantastic.
martin