Biggest question is what is the most complex game you see yourself playing on this system and are you looking to save money and get just what is required according to games you listed and other games of similar complexity for processing power for CPU and GPU?
The build you shared is a strong build and so if you can see yourself wanting to play more demanding games in the next 5 years then I'd go with the initial build. However if your going to stick with the most complex game being = to Diablo 3, then a Core i3 would even work paired with a good video card.
I for example built up a newer 8-Core AMD FX-8350 4Ghz with 8GB DDR3 1600Mhz RAM running Windows 7 64-bit as a gaming system to replace my 6 year old Dual Core AMD Athlon 64 x2 4450B overclocked 10% to 2.53Ghz with 4GB DDR2 800Mhz RAM running Windows 7 64-bit and the 8-core is overkill for all current and prior games I own for it. The Dual-Core older gaming system wasnt lagging, but I felt a need to buy into a newer system to have more processing power. Fact of the matter is that, I probably could have saved my money because the system that I already had that was 6 years old had no problems and played the games fine. Additionally my power company decided to raise the rates of power kWh to double what we paid prior this past winter and it made more sense to run the 130 watt 6 year old system instead of the 465 watt 8-core system playing the same game titles. Currently my 8-core system hasnt been booted in over a month and I have continued to play on this older system which plays World of Warcraft, Diablo 3, Hearthstone, Steam Games from the lesser complex indie games to more complex games like Skyrim, Blades of Time, and Guild Wars, and Guild Wars 2, and Tera Rising etc without any problems in performance at normal settings with 30 to 60 fps. My 6 year old Dual Core is only about 1/3 to 1/2 as powerful as a current Core i3, while the 8-core system is 3x or 4x more powerful than a core i3 and is matched in benchmarks to some i7 processors, with other i7's way faster than the 8-core AMD.