Are you looking for a 4u case and what part of the world are you buying from?
homelab
4u would be fine, I’m in the UK
This one looks kinda interesting. https://www.amazon.co.uk/INTER-TECH-Storage-88887191-Case-without/dp/B015FA61K2/ref=sr_1_20 https://www.scan.co.uk/products/4u-ipc-4u-4408-storage-server-case-w-o-psu-supports-8x-35-25-hdd-2x-80mm-fans-2x-usb-30
This looks ok. https://www.scan.co.uk/products/codegen-4u600v2-4u-rackmount-v2-600mm-deep-butterfly-lock-includes-2-x-80mm-and-2-x-120mm-fans-atx-m
The second link you sent looks promising, the codegen one isn’t very good apparently, seen some reviews on it and it didn’t have the best build quality.
I bought all new because used market around me isn't big enough. I went for Silverstone for the case (both a 4U and a 2U), and Startech for the cabinet. Cabinet is expensive new, but apparently in some places you can get used for cheap.
The 4U case (RM42-502) is for my PC so I have a full size 2080S GPU, an ATX motherboard, but not that many SATA drives, but I know they are selling either mods or other cases in the same form factor. Since temps and noise were a big priority, I went with a Noctua D12L ventirad. Only downside compared to normal case is the cable management that is a bit more tricky imo.