Even if something like proxmox or a Debian install with docker is more customizable. It’s a steep learning curve.
But isn’t something like truenas scale a option? I run Emby(as my media Server) and the arr’s on it. All the apps are already in the “software store” including plex. And setup of the arr’s is just the same as normal. All installs are basically automatic.
I easy passthrough my intel gpu in the config page on the webportaal, but don’t how easy it is for Nvidia or amd. Especially with Nvidia due to drivers. But maybe someone here knows?