Travel (small) ATX PC case

[RazorGreen18]

I have recently bought my HTC vive, and I have had my gaming PC for about a year now.
Along with getting a vive, one of the best things to do is share the experience, as most of you know.
My small issue is my pc case size and weight. I have a rather large heavy case and it is a pain to move and transport to take the vive to peoples houses or even move it around my house to play vive in the living room. I don't want to change pc parts to fit a new case but I just want a smaller more travel friendly case. My current PC specs are below, if you guys could help recommend some case options under $100 US. The case needs to be ATX compatible.
Also I am considering getting a slimmer CPU cooler if needed when getting a smaller case. I can't remember my cooler's model off the top of my head right now.
Thank you for your time!

MOBO: GIGABYTE G1 Gaming GA-Z170X-Gaming 5 (rev. 1.0) LGA 1151 Intel Z170 HDMI SATA 6Gb/s USB 3.1 USB 3.0 ATX
GPU:GIGABYTE Radeon R9 390 DirectX 12 GV-R939G1 GAMING-8GD 8GB 512-Bit GDDR5 PCI Express 3.0 HDCP Ready ATX
RAM: CORSAIR Vengeance LPX 16GB (2 x 8GB) 288-Pin DDR4 SDRAM DDR4 3200 (PC4 25600) Model CMK16GX4M2B3200C16W
I have a standard HDD and SSD also.
Need slim CPU cooler for LGA 1151 i7 6700k

 

[little_me]

small and ATX don't really fit together too well.
https/www.amazon.com/RIOTORO%C2%AE-CR1080-Compartment-Support-Dedicated/dp/B01D205IXS/ref=sr_1_10?s=pc&ie=UTF8&qid=1471210680&sr=1-10&keywords=%22full+atx%22
from:
http/www.tomshardware.co.uk/answers/id-3154636/smallest-full-size-atx-case.html

Downside is maximum GPU length of 300mm (according to the page, possibly limiting it as a choice)
Other alternative would be to change the motherboard to micro ATX or ITX which in turn would hurt availability of other components/space.

Edit: As alternative http/www.corsair.com/en-gb/carbide-series-clear-400c-compact-mid-tower-case
which isn't small (it really can't be as ATX) is still somewhat... small-ish.