As I said in another post on this forum, go and visit the various schools and then make a decision.
Questions you need to ask: Do they have a full-time CFI? Do they have full-time management? Do they have a full-time dedicated ground school instructor? Do they have their own AMO?
Also, speak to their current students. If they recommend the school, you know you have a winner. If not, look somewhere else.
In Joburg, try FTS and SAFTA.