Save, save, save for deposit!

This news article on property24 explains in detail what the benefits are if you could save for a large deposit. 

Save, save, save for deposit!
http://www.property24.com/articles/save-save-save-for-deposit!/12079

“Furthermore, homeowners who contribute from their own pocket to finance a property are considered a lower risk of default to the bank, which means the bank can offer a lower interest rate on the home loan. Even a 1% reduction in the interest rate on your home loan will save thousands of rands over the term of the bond. These savings, in many cases, add up to far more than the deposit amount,” says Goslett.

(via Instapaper)

One of the factors banks take into account when approving a home loan and determining the interest rate is the "loan to value" (LTV) ratio. As mentioned in the article, the lower the LTV, the better your chances of getting a rate reduction.