It is fairly easy to convert an EASA licence into just about any other ICAO licence - all that is generally required is to take a single multi-choice exam with the new authority and sometimes but not always take a skills test.
However, to convert another ICAO licence into an EASA licence is much more difficult - almost without exception you have to follow a prescribed course of study (expensive) then take several multiple choice exams, and then take at least one, if not two skills tests.
So if you are sure that you are going to pursue a career outside of SA, and have an opportunity to do an EASA licence in SA at similar cost to an SA licence, then take the EASA option.