Don't have a moment to review your full build, but as far as 1440p monitors go, I've been loving my HP Omen 27q.

MSRP is $300, but it's pretty regularly marked down to about $250. Amazon has it at $247 right now.

Handles HDR, up to 165 fps, fast response time, has variable refresh rate so no screen tearing when fps dips happen.

My only issue with it is that it's "eye safe certified" which effectively means that it has a warm color tint forced. My eyes adjusted very quickly, and I use software to reduce eye strain on my other devices, but as far as I know there isn't a good solution if you're mixing monitor types. Using Window's "night light" mode or Flux would make the Omen too orange to adapt to when my other monitor would be too "blue" at night without the software color adjustment. I ended up just buying another Omen in the end for dual monitors.