Is it a bad idea to build in an mITX case w/ this hardware? (Or case alternative?)

So, just asking generally, (I know there's obvious requirements in regards to space constraints):

I'm still in love with the Manta cases, but here's what I'm hoping to pack in the system I end up making a configuration for (I just want a case that's ideally smaller, and deviant from black box):

- 16-32gb RAM (undecided)
- 2SSD (boot, game), 1HDD; or 3 SSD
My main concern:
- Intel I7-6700K
- GTX 1080TI

- Closed loop cooler (if such a thing exists, akin to the H60 from Corsair they made for larger systems).

I'm unlikely to bother with overclocking. I got the i7-K cause the K was a deal.

Is it foolhardy to try something like this? I've had people mention "cooling will be a nightmare" but I've never done an itx (or matx) build before.

If not, memory express in Canada.... does anyone have case suggestions? I'd like to avoid full ATX and I would like something that isn't just a plain black box.