Hi this will be the 1st time I'm building my own system for gaming. However, I have no idea what parts to use. I want something that can run Guild Wars 2 well. I already have the peripherals. So all I need are the necessary hardware and also an OS, preferably Windows 7. I plan on buying all the parts from Newegg.com, and I intend to spend around $800, or $850 max.