My advice would be:
1. Go to Namibia- have run into too many sketchy outfits in RSA
2. Book your travel through someone accustomed to travel to Africa. Gracy Travel, Steve Turner or a couple others. They will be able to answer all your questions about the trip.
3.Take or have access to more money. Take less clothes.
4.Be mentally prepared to go back..you can get financially prepared later, because you'll be planning your next trip on the flight home. Guaranteed.
