Pretty good system, but just a tip - you won't need to spend so much on a PSU. You will only need 500-550 W. (with 30 amps on the 12+ volt rail minimum. just look at the model you choose for the amps 12+ specs.) Happy to help!
I'm not aware of the average prices for components in the UK, but judging on the parts you've selected, it seems to be a very good budget orientated build. Also, take the advice "thenightwatchman" has given you, that build will run you at max only 450-500W's, 550 if overclocking, so go with a PSU from XFX, (the one you have in your current build is good), and just lower its wattage. You'll save a few cents.