Mid-end build with entry level graphics; can't really go wrong here with the i5-2500K and a good power supply that will come in handy if you want to upgrade to a more beefier graphics card later on.
My first concern would be upgrading, though.
The motherboard you picked out only has one PCIe x16 expansion slot. Your HD 6670 will not be able to play many modern games at high resolutions:
http://www.techpowerup.com/reviews/AMD/HD_6670/11.htmland it would be convenient later on to get another HD 6670 and run them in Crossfire.
Asus P8H61-M Rev 3.0
http://www.newegg.com/Product/Product.aspx?Item=N82E16813131716 ($80.99)
Gigabyte GA-Z68AP-D3
http://www.newegg.com/Product/Product.aspx?Item=N82E16813128538 ($94.99)
For 14 bucks more you get 2 additional RAM slots that have the ability to run at up to 2133 MHz, an extra PCIe x1 slot, an extra PCIe x16 slot, SATA 6 GB/s and two USB 3.0 ports.
According to the bad customer reviews on the WD Caviar Green drives here:
http://www.newegg.com/Product/Product.aspx?Item=N82E16822136513Many dead on arrival drives.
It is possible that the "Green" Drives were originally high-performance drives that failed to meet the stress tests in the factory and therefore were binned as lower performance drives.
