Expat Health Insurance Partners
Aetna International
Aetna is an award-winning insurance business that provides health benefits to more than 650,000 members worldwide. Their high quality health insurance plans are tailored to meet the individual needs of expats living and working abroad.
Cigna Global
With 86 million customer relationships in over 200 countries, Cigna Global has unrivalled experience in dealing with varied and unique medical situations and delivering high standards of service wherever you live in the world.
South Africa issues critical skills work visas that last for 5 years.
From my knowledge, there is no six-month option or any other options that allow for a period shorter than five years.
The advantage of the critical skills visa is that you can live in SA and look for a job for up to 12 months.
I recommend contacting an immigration company. They have expert knowledge on this kind of thing. Otherwise, this Expat Arrival's page on work permits in South Africa might be useful.
Hope that this helps.
-Kyle