Your CPU and board selection would not be right given your current budget... in fact it's not right for any gaming rig, really. You need to get a 2500K or 3570K, and a Z77 MB. This will save some money for the important PSU and a better GPU... which will have a big impact on gaming.
That Proximon build has you back on track. Not really any benefit for you to build on the x79 platform in this budget range, much better off maximising that GPU. As posted by Proximon if you can stretch that little bit extra for a 7850, you're looking at a serious GPU, otherwise to keep you in budget, you could look at the gtx 560 which is no slouch, but no 7850 either.