Is the server going to be headless, or dual purpose of server and desk top?
If the only intended use is a personal server, I would suggest looking at a RPi4b SBC and the Argon 1 case. The Argon 1 case has the option of a replacement “bottom” that integrates a M.2 SSD into the case. See this post for further details. I personally do not have the Argon 1 case, but it sure looks interesting.
This post in the same topic for a discussion of server hardware.
Pudge