I would go for the HD 7850 at Wootware (R2000):
http://www.wootware.co.za/computer-...rd-includes-2-free-games-amd-silver-tier.html
It's faster than both those cards and it comes with a digital voucher for 2 free games (from a pool of games).
Seems you are looking at Rebeltech. In general, Rebeltech is cheaper than Wootware, but in the graphics card department, Wootware has some very nice specials on Powercolor cards. Powercolor is not as established as other brands like Sapphire, but I have had no problems with my purchase (Powercolor HD 7950 Boost). I have had it for about a month, playing demanding games constantly.
Long story short, I would go for the HD 7850 for the best bang for your buck.