The motherboard may be a bit overkill. The RAM as well, especially for gaming (it will take a long time before games use more than 8 GB). The PSU is fine, though if you don't plan to add a second graphics card you should get a lower wattage PSU.
Those cases are both good, main drawback is they don't have front panel USB3.0.
You could get a faster SSD, though it's not going to make a huge difference.
I'll go with 8gb then, and which motherboard do you recommend?
Is it worth getting the gtx 680 as well?