This was a tragic but fun build. I wanted to have top-class parts but in a mATX case.
I purchased a Corsair H150i Pro and a Fractal Meshify C Mini case - after reading the dimension specs for the non-mini version of the Meshify. So of course, the radiator didn't fit (by like 1-2mm). But I really liked the Meshify C Mini, so I took a hammer to the case. It fit.
I then got myself a Gigabyte Aorus 2080 TI Xtreme, which supposedly should've fit from the manuals, but again it didn't fit by a frustrating 1-2mm. After thinking for a little while, I decided to move the two bottom front fans from inside the case to outside the case, but behind the dust filter mesh. The mesh actually bulges out minimally, but it's actually unnoticeable without close inspection.
End result? Around a 1-2C increase on my CPU (which I'm okay with), and a beastly machine. Temperatures were a bit crap for the card at first (way too close to the PSU due to case size), but after setting an undervolt of 0.950V, the GPU never reaches 80C @ 2000mhz. I'll call that a win.
The 9900K runs at 5.0ghz @ 1.290V. Under 80C on load.
Got the RAM from a Newegg sale. Running @ XMP profile.