So I've done some research on how to figure out the wattage, and with capacitor aging set to 50%, the result I got was just under 600 Watts. I also heard you should leave some room for upgrades, so I settled on the EVGA SuperNOVA NEX 750W 80+ Bronze Certified Semi-Modular ATX Power Supply. Would this be a good choice. I'm also a first time builder.
Parts list: http://pcpartpicker.com/p/q4PBJx
Parts list: http://pcpartpicker.com/p/q4PBJx