Asus M5A78L/USB3 Motherboard £60
They don't sell that proc anymore from what I'm seeing on amazon but the 965 is £79.49
HaF 912: £70.49
If its this power supply I wouldn't trust it in anything: http://www.newegg.com/Product/Product.aspx?Item=N82E16817341002
700w, 4 12v rails and only 2 pcie connectors... wut?
Never heard of that wifi card, can't find current prices.
Ram is fairly cheap, never heard of that brand but a single 8gb stick is almost 50 http://www.amazon.co.uk/Corsair-CML8GX3M2A1600C9-Vengeance-1600MHz-Memory/dp/B00569K7LM/ref=sr_1_9?s=computers&ie=UTF8&qid=1341778035&sr=1-9
Lets assume the psu is 50 the total comes out to around 410 without the os or drives and if you bought everything NEW.
You can't really tack on an extra 200 bucks for the highest version of windows since you don't know what they need, 99% of people don't need windows 7 ult and I have no idea what drives those are.