Originally Posted by ThePoundDollar
I sound like such a nagging twit don't I
Haha no ofc you don't, you're spending a considerable amount of money and I'd think you were a twit if you didn't want to know these things.
The build I've suggested would rip the Dell apart. It has an SSD for faster OS loading times and just overall improved opening times when using Windows. The GTX 670 I've suggested will comfortably beat all of Dell's offerings and the GT640 that you get with the 8500 is terrible for gaming so there's be no point buying it.
I could make a build closer to £700 if you want that would show you what sort of specs you could get at the lower end of your budget if you want, but I strongly advise you wait a little over a month and get the newer kit.
*edit* Most importantly over the Dell all the components I've selected are high quality and reliable whereas Dell (like all prebuilt companies) will cheap out on things like the motherboard and power supply.