Debian, always debian for server type things, BUT, it might be more versatile to put VMware ESXi on it. (or Proxmox)
https://github.com/itiligent/ESXi-Custom-ISO
This repo has working scripts to inject into the ESXi installer ISO with all the drivers you need to get your NUC running as a virutalization host. (Recently VMware was aquired and all the community driver sites were taken down, so other online build tools stopped working)
I run a homlab with a cluster of ESXi NUCS , its just sooooo useful especially when developing code for differnt platforms or just quickly learning things and tinkering about.
I concur with u/Bellegr4ine amd will add a little more:
I do this and is allows me to run a family LAN network and also to have a completely separate internet environement for my lab