Oh another Cosmos, I love this case which I upgraded from a MB 510 or 520 (I do not remember, the Noctua NH-D15 was too high for it, it bended my plastic side panel...hopefully it was not made of glass).
Your PCs look really clean, mine is an ugly mess (like my desk) despite the massive available space of this case. I have the C700P Black Edition (less expensive plus I am not that a LED guy).


My PC is a mix of 2019 Q4 material and more RAM + 3080 + PSU + Soundcard from 2021-2022.
Cosmos C700P Black Edition
Antec signature platinum 1000W
Asus Z490-E Gaming
i9 9900k
Noctua NH-D15
MSI Ventus RTX 3080
Corsair Vengeance 3000 c15 64gb (4*16)
Samsung 970 Evo Plus 1 tb
Corsair Force 3 120 Gb (from 2012)
Kingston 120Gb
Samsung Spinpoint Fomula 1 tb (from 2008 !)
ASUS BW-16D1HT (Blu Ray)
9*Noctua NF-A14 (including 2 bottom, I purchased the thing on Cooler Master website, honestly it is mostly useless compared to let's say 6 fans)
Soundblaster AE-9
Asus Extension Fan II (not trully supported by my motherboard but it works at fixed speed)
Samsung C34J791WTU (though I play 80% on the time on my TV using a ruipro 15m fiber optic hdmi cable)
There is also a little guy on the third photo, a NUC11TNHi7 with Crucial 32Gb 3200 and a Samsung 980 Pro 500Gb which I only use for dev (Docker, etc.).
I'm also waiting hard the Steam Deck... (hopefully on Q4)