I've just been looking online places to buy cos I'm upgrading. you can win a custom pc with one company that sell on eBay. tweet @FreshTechHQ with what you want and #PCGaming. better than a shop because it's free! i'm definitely having a bash. then I'll carry on price checking if I don't win haha.
I like AVA Direct. They sell their own branded machines as well as some other popular enthusiast brands (Sager, MSI, ASUS). They have very good customer service and technical support.