Overall it's good but your PSU is overkill, you wouldn't need anything more than 500W, and even that would be more than enough but just stick with 500W so you can upgrade in the future when you want to. I'd go with a different PSU brand too, Corsair, Seasonic are really good brands.
Diablotek PSUs are absolute junk, one of the worst brands on the market. The Radeon 7770 is OK, the 6870 beats it in most tests. Better would be to go with a 560TI and Core i3-2120. That Green hard drive will also be a massive bottleneck in most games, you want 7200 RPM minimum. An SSD is ideal, but not for a $700 budget.