A single GTX 680 with no plans to SLI does not need a 750W PSU. It is far better to get a higher quality 650W given the same prices. The Seasonic X650 is one of the best ever made and is fully modular, not a hybrid. It's also one of the quietest as the fan won't even come on during normal loads. http://www.newegg.com/Product/Product.aspx?Item=N82E168...
Your (Intel) PC as listed will only draw about 300-350W under load.
Your usage is ONLY gaming, no video editing or such, so there is absolutely no reason to get the AMD build. IF you did need all the cores and were going to to use say GTX 670 SLI, I can see an argument for the FX-8350. Still not a great argument but if, say, you really wanted to support AMD and gaming was only half of your usage, then possibly. The FX-8150 would not be considered though.
I think you had listed a Lian Li case earlier. I respect high quality cases a great deal. I upgraded from a Silverstone TJ09 to a CaseLabs M8. I do not believe that Lian Li case is worth the price.
You only need 8GB of RAM and you should never buy two kits. Buy one set and leave the second pair of slots open.
I'll cook up a newegg list as a counterpoint to Emelths good list: