If you are going AMD, get a cheaper CPU, something like Phenom II x4 955 BE for gaming it's just as good as the hex core for much less money. If you plan on upgrading to bulldozer CPU's when they come out you could even go lower on the CPU, an Athlon x3 would nicely run your games until the bulldozer CPU's are out.
I had problem in understanding that site,whatever I could understand was that there is huge amount of tax, and the components were overpriced. so i give you the build based on newegg.
Also you can save some money by getting Windows 7 Home Premium rather than the Ultimate one. You get almost all features except those that may be needed for big enterprise in networking,etc.
Motherboard : $145- Gigabyte GA Z68X
Can run dual graphic at 8X/8X. Has USB 3 support,etc. Its cheap as well.
Case: It's your choice what kind of case you would like. Here's my choice CoolerMaster HAF 922 ($100) If you choose any other case ensure it has good airflow and size good enough to accomodate 2 Video Cards.
Power Supply: $110- Corsair Enthusiast TX750. Sufficient for your gaming needs and overclocking. If you don't find this one try to get a power supply of atleast 750 Watts, that's atleast bronze certified from a reputable brand.