if you want a good flight school close to joburg,try lanseria flight centre.i trained there and am doing my cpl with them and i have to say they're pretty jacked up.Lanseria is also a fantastic airport to train at because its very busy so you learn from the beginning in a real world environment,which is invaluable as a student pilot.
they also have a good fleet of c172,be76 and pa28r aircraft as well as a c182 (i think?). honestly though, i would highly recommend them. their number is +27 11 659 2810.