Dont think you get DIY rubberising, the ones you normally get for DIY is stone-chip. It is also a good coating, but it is very hard, so it scratches the stuff you load, where genuine rubberising is rubber, and do not scratch anything.
It costs a lot, for a 1400 bakkie I guess it would be near R2500. Phone around for prices, I know of Rhino linings. Yellow pages have lots of adds on bakkie linings, but just make sure it is rubberising, and not just a lining.