what would be the most cost effective way to get a server chassis or prebuilt server, that is 2u, 25 bay, that has at least PCIE 3.0 U.2 connectivity for the drive bays? finding stuff like this on the used market is much harder than just a traditional SAS backplane, probably due to it just not being as popular, or being a newer standard, I'm not really sure. Any help would be appreciated, even if its just a link to an article to educate me on why I'm stupid.
Edit: I did find this enclosure, it states "NVME" support, it doesn't specifically say U.2, but as far as I know that is the only way to have NVME support on the backplane. does this mean that this enclosure has U.2 support? Here is the link
Why do you want 25 bays of NVMe? That is an absurd amount and almost no system, especially used, is going to have enough lanes for that.