Not able to find an answer and consulate has not responded.

I will be spending 7 months in Southern Africa (Sept - Apr) of which 162 days will be a self drive 4x4 in South Africa, Botswana, and Namibia starting from either CPT or JNB. My preference would be to start JNB and drive to Namibia or Botswana within 72 hours of arrival. This will allow for visit to the north during a drier time. I then will spend the final 90 days within South Africa.

Here’s my understanding for a U.S. citizen: A 90 day tourist visa can be obtained on arrival and is consecutive days. In order to get a new visa I must “return to your home country”. This, of course, won’t work in the proposed scenario. So my question is: Is there such a thing as a transit visa that would allow for SA arrival and transfer within 72 hours to a neighboring country and then get a 90 day tourist visa when I return (without the home country requirement)? Preference would be via ground (4x4 rental) but could fly WDH and start 4x4 rental there.

Thanks