This is my chosen build as it is. If you would improve a component, make sure the total (more or less) stays in the same price range. Please comment and say if its good or not, and if anything's wrong with it. (Note, I'm not changing the GPU. I'm getting it from a friend for dead cheap.)
Purpose of PC: gaming.
Will overclock CPU.
CPU: Intel i5 750
Mobo: Asus P7P55D-E Pro
RAM: 4GB Corsair DDR3-1333MHz (2x2GB)
GPU: HD 4890
PSU: CoolerMaster Real Power M620
Case: CoolerMaster HAF 922
Edit: I am geographically constrained to South Africa, and so specials won't be of much use to me. If you want to make an improvement to my build, then rather say "Instead of the i5 750 get the i7 860, because yadiyada." "Get 1666MHz RAM, because yadiyada." "You need a better PSU, at least 2000W" etc.
RAM: G.Skill Ripjaws 1600 mhz CAS Latency 7. I'm sure they're cheaper. Didn't see the "buying from a friend" comment.
Case/PSU: If you're in the US (maybe Canada as well), you can get the HAF 922 and an OCZ StealthXStream 700W for $110 after rebates from Newegg. This would be better than that PSU, and most likely cheaper.
GPU: Hopefully, with the couple of change above, you'll be able to get an HD 5850. If not, save some money and get an HD 5770. It's a little lower powered than the 4890, but more future proof with DirectX 11 support and being better in Crossfire.
It will handle Crossfired easily (maybe need an adaptor for larger cards). So for 1 card, it is overkill. That said, it is very hard to get a quality PSU for less than that, so you won't save anything be going smaller.
That depends on the CAS Latency. Typically, Corsair sticks are just overpriced for their specs. You can usually get faster sticks with tighter timing for the same or less. Nothing wrong as far as quality.
Thank you for the South African site links. I prefer to buy hardware from a shop, but if the place I'm buying from can't supply me with decent RAM then I will surely get it from IkonicIT. They offer great prices.
I've just decided that I'll get the cheapest CL7 RAM available, but I'm still a bit stuck on which PSU ... I'll browse a bit more and ask for opinions later