Nice, I just put together my similar build. I started with an H115i but temps hit near 100C (Prime95 w/ AVX) with the 9900K cranked up to 5Ghz so I replaced it with a custom loop. Your results may vary. I kinda wish I had gone with fans that are compatible with RGB Fusion software, but I like the Corsair fans and the Corsair Commander Pro. A plus is there is a nice place to mount them.
For the M.2 screw, see if one came separate in the box. I believe that is how it was with my Z390 Aorus board.
Can't wait to see how yours turns out.