Both are very nice builds, but for gaming you could do slighly better on the AMD side. You could also add en FX8350 if you prefer. but both cpu´s are basicly the same, only the FX8350 is higher clocked out of the box. If you just bump up the cpu ratio on the FX8320 it will run the same speed.
If I were you, and as you're only using it as a gaming machine I would go for the WD green 2TB rather than the 1TB black. Other than personal brand preference they're nice :)
Greens die quicker and are slower than blacks. Wd black drives are the only drives I will use currently. When ever I try anything outher than blacks or reds they tend to die quickly. I have gone through so many greens, blues and barcuda's while my blacks are still runing after 6+ years.
Cpu intence games love to lap up the dingle core performance of intel. Games like battlefield and kirbal space program. But for most games the fx 8000 series are perfectlyfine. If your doing any sort of video editing and such grab the intel. The higher temp cap and lower clock speed is really worth it in terms of stabiloty in any sort of work station environment.
Also, windows 8 is slightly better optimised for the AMD build and although games will eventually start to take advantage of the greater number of cores, they're not there yet. But mantle does look promising.
What do you plan the life cycle of this PC to be? Before you replace it.