You should be able to put something together for that. And yeah, have a nose at Overclockers.
As a rule of thumb a grand will get you a kick ass one if you build yourself. It's not quite as simple as chucking all the money into the GPU. Taking NVidia (I'm not up to speed with ATI at the moment) there's normally a huge price difference between the x80 and x70 (680, 780 etc.) and in this particular round and the last things became muddied between 670 and 680 when they brought in the 660ti which was only a little shy of the 670 but quite a bit less in cost.
Similarly, on the processors, it's not so clear cut any more. First up you have the K versions that are unlocked for overclocking. If you're into that. But you pay a premium for them so there's money to be saved if you think you'll never overclock. Also, last time round I looked into getting i5 rather than i7. I still went i& anyway because I'm a whore for power, but the bottom line, from the best I could tell was that the main difference between i5 and i7 was the hyperthreading and the virtual cores which mean that unless you were going to be doing a bunch of stuff with VMs, you'd gain little from the i7 over the i5 and could save a wad of cash there as well.
As is happens, I run windows in a VM from OS X all the time at the moment (and can barely notice that it's a VM) so I'm glad I went i7
There's loads to it, but the cost savings can be very beneficial. Last one I built was for my nephew. My cousin was quoted just shy of £2k for his gaming system. I built the same system with just a couple of cost saving tweaks for a little over £1k.
