Sue,
For the safari I wore vest tops with an over shirt and 3/4 shorts you do not need walking boots as you don't really get out and walk into the bush your on the jeeps most of the time. You will need a fleece perhaps for the evening.
The case that goes on the safari hotel has to be soft sided like a sports bag, as once you leave the airport your in the jeeps and they cannot take loads of hard cases.
If I can help with anything just ask ..You will have a great time on this tour the animals are amazing.
Cindy