First time building a gaming pc. Is this a good build?

This looks like a very good build, you're good to go.

I'd recommend western digital for hard drive, and Corsair or Samsung for SSD.

OCZ is also a very good choice for the SSD if you get a Vector or Vertex 4 - the other, older models aren't nearly as reliable.

The only other thing that stands out (other than the case not being to my taste  ) are the graphics cards.

A single 7970 will be able to max most games at 1080p and 60hz. What monitor setup do you have?

Crossfire:
Your main issues here are:
a) micro-stutter (a large issue regardless of what many think)
b) Crossfire doesn't work as well as SLI (in number of games and performance, on average)

My advice is get the best, single-GPU card you can afford. Make sure to look at:
a) cooling and noise
b) relative performance (for example the Asus GTX 680 DC2T is up to 12% faster than a stock 680)
c) customer reviews (especially if they died)

NH-D14:
I own this cooler, however the fans are VOLTAGE-controlled only. You likely want a cooler that supports PWM, then tweak the fan setup in the software you get from the motherboard site.

Optical Drive:
*Make sure to investigate the date of the last FIRMWARE from the drive's support site. The older the firmware, the more likely it is that a burn will fail. 2012 or newer. (also, some motherboard SATA connections are for hard drives only. They will work but give you burn failures.)

SSD/HDD:
Just FYI, but Steam allows multiple Steam folders. My setup now is more like this:
SSD#1 (128GB) - Windows/apps only.
SSD#2 (256GB) - 2nd Steam folder (smaller is fine. see below)
HDD#1 (3TB) - everything else, including the main Steam folder, Windows drive image backup via Acronis True Image etc.

*Steam 2nd folder, and MOVING GAMES:
Most games don't benefit much from an SSD, however rather than spend lots of time investigating I just got an SSD and simply MOVE games from Steam to this SSD when I'm playing them (even a 60GB SSD would handle a few games):
a) Backup the Steam game (on HDD)
b) Delete the Steam game
c) RESTORE the Steam game (but now choose the SSD folder)
d) Delete the backup (if desired; manually, from the HDD)

Huh?
For example, by doing the above I essentially MOVED the game Skyrim from my HDD to my SSD. Now entering building and jumping locations is much faster. When I'm DONE I'll move it back to the HDD (or just keep the backup on the HDD).

Save Games shouldn't be affected unless the save files are in the game folder so you may wish to investigate that if needed.