Depending on size requirements, there is also the node 304 case
http://www.fractal-design.com/home/p...node-304-black
In the following I assume you won't be overclocking. If you want to overclock, you should look toward water cooling with such a small case.
CPU: Same as said above, for just gaming I'd go for an i5 or at last a "cheap" i7. If you don't plan to overclock, you can skip the K models, cutting money there too (depends on your local market).
Cores don't play that much of a role in games. Above 4, it shouldn't be felt at all, the difference between 4 and 8 is actually never felt in any application except for rendering/encoding and servers etc.
An i7 4790 should be plenty for gaming.
MDB: For the motherboard you usually don't need the fancy chipsets, most of the time the difference is about the latest usb, raid and overclocking capabilities.
Usb is debatable but raid and overclocking shouldn't be a priority for a miniITX. A Z97 should be plenty enough.
I go with Asus motherboards.
As said above, cut a bit on motherboard and cpu and put it into 16gb of ram, a good CPU cooler and a bigger ssd.
CPU cooler: In my experience,
Noctua strikes a good balance between silence and cooling power.
The case linked above should be able to accommodate some of the big desktop coolers.
VIDCARD: The 970 seems to be a good deal if you play at 1080p, for higher res, it might be a bit short. I was looking into one recently and the
asus stryx came up, mainly because it seems very silent.
STORAGE: You'll definitely be annoyed with a 128Gb disc, aim for 256 or even 512Go. Samsung EVO 850 (cheaper, a bit slower) or Sandisk extreme pro.
You want windows, all apps and all games on the ssd. Trust me, 128Gb could be fine for an htpc, or an MS office machine, not much else.
Hope it helps and hi btw, my first post :)
Cat