So after much consultation with some of the experts here, I finally came up with something.
MB: Asrock h61
CPU: Intel Core i3-2100
RAM: G.Skill 2x2GB Ripjaws 1333Mhz DDR3
VC: Sapphire Radeon 6870
HDD: 320GB Seagate 7200RPM
PSU: Silverstone Essentials 500Watts
I was told I don't need to buy a cooling system unless I over-clock which I don't think is possible with the i3. So is the set-up ok already? Comments greatly appreciated. Pang gaming ra ni. Just want to get SC2 and DotA 2 running on good fps.