MCPRUE sells shameless ripoffs of the Mac Pro case, but with support for standard motherboard sizing, if you really want your PC to double as a cheese grater: https://www.mcprue.com/case
P.S. Does anyone know how well Studio Displays now work on Linux? The best I could get it to work was on Ubuntu, where it basically worked out of the fresh install. X11 KDE on Fedora was a close second. Couldn't get it working on Wayland whatsoever.