You could aswell go with a 670 since it's barely slower than a 680 and save 100-200$
If you are not fixed on Nvidia, the 7970 / 7950 is a great choice aswell! [7970 > 680]
PSU seems fine, although the lowerend corsair PSUs are not that awesome, maybe check with seasonic.
Mobo: Some may claim it's overpriced, but it's a good mobo. It survived my loop leaking for a few days without me noticing, and still runs perfectly fine. Otherwise, Gigabyte UD3 / UD5 / UD7 are very nice boards.
HDD seems fine, using one of those
SSD perhaps go for a 128 Samsung 840 pro, more reliability / speed
Cooler is fine.
Extra fan is crap, BitFenix Spectre if you are looking for quiet LED fans.
Drop the optical drive if you don't really really need it. [You can install the OS from a usb stick].
Those are good parts but, the build as a whole needs some improvement.
You can get similar performance from an fx8350 and save yourself some money to invest in a better gpu or more ram. On the subject of ram, you didn't include any. for the gpu unless you need the cuda go with a 7970, it's cheaper and faster. You may even be able to get two 7950s in crossfire, though that can be buggy.
Meh, the fractal fans that came with my define mini both were not working after 2 weeks, luckily by yelling enough at the guy in my PC store, I got 2 noctuas as replacement :D