What I had in mind (design requirements): small, quiet, under $1500, plenty of RAM and an i7 for Matlab, maximum gaming performance
Reasoning behind each component's selection: i7-6700: didn't want to bother with overclocking in such a small case with limited cooling and figured I'd try the stock cooler until I find that I need a quieter/more effective one
GTX 1070: The 1070 came out at the end of the week where I had planned to purchase parts, so I was easily persuaded to wait. Managed to snag one on the 17th on the third try. Worked out nicely since the G1 Gaming has a custom card and cooler.
Motherboard: Mini ITX, WiFi, M.2, plenty of USB ports/headers, and was a bit cheaper than the Z170 version
RAM: 2133 MHz is the max supported by the H170 chipset so anything faster would see no gains
SSD: solid state seemed cool, M.2 seemed cool, Samsung 950 Pro seemed really cool but some reviews said you won't notice the difference outside of synthetic benchmarks and a few specific scenarios so I opted to get double the capacity and save money
Case (with bundled power supply): Finally, a case that didn't have tons of space I didn't need and wasn't a cube like the CM 110. Reorienting the video card with the rider card does wonders for the form factor. The 450 W PS seemed to suit my 283 W estimated draw. Unfortunately it isn't modular, but without a window to view the mess and with saving around $50 it made sense.
Fan: Other builders with this case noted improved temps with a fan (duh), so I decided to try one. There's space for a second one if need be.
The Build: Even with the cramped case and this being my first build everything went smoothly. Only took a couple of hours (including time spend staring at the shiny new 1070 before hiding it away).
✓Small: about as small as you can get with a full size video card
X Quiet: stock cooler and video card can be loud when under heavy load
✓Under $1500: about $1370
✓Plenty of RAM and an i7 for Matlab: 32GB and 6700
✓Maximum gaming performance: the GTX 1070 seems to perform a bit better than my old Radeon HD 3400
CPU Temp: Idles at 30, settles around 75 under load, but jumps into the high 80s and bounces off the thermal throttle if it runs at 100% for more than 5 minutes. A new CPU cooler may be in order...
GPU Temp: Idles at 32, settles around 72 under load with the fan profile set to the "quiet" preset.