Piracy: ꜱᴀɪʟ ᴛʜᴇ ʜɪɢʜ ꜱᴇᴀꜱ

You'll want to look at either Plex or Jellyfin for your front-end streaming clients, personally I prefer Jellyfin for its customizability. For sorting media, you'll want Sonarr for TV-Shows and Radarr for movies. To find the magnet links to send to Sonarr and Radarr you'll need something like Prowlarr which will pull magnet links from the sources you'll specify. With that out of the way you'll need some way to take those magnet links and actually download from them and for my I prefer to use qBit, but any torrent client will work, just make sure to put it behind a VPN. Lastly, I'd set up Obmi to allow your users to make requests. In regard to the OS why not use something like TrueNAS compared to the guide which suggested Ubuntu, I've found the UI in TrueNAS Scale to be much easier to work with especially since all the services I mentioned are apps that you just pretty much one click installs.