Just set this up a few days ago and so far am very happy. Ended up choosing it over other options since I wanted something that saves the downloads in a humanly accessible way by simply putting them into channel folders with the video names as title.

If you want to setup a stack take a look up TRaSH guides. Then it goes roughly like this.

You have software that search and make the download requests: radarr (movies), sonarr (TV shows), lidarr (music), bazaar (subtitles, if you need to add more that don’t already come with the movie/show). But there might be others e.g. for porn or like here for YouTube.

Those forward the request to a downloader like Sabnzb if you are using usenet or qbirtorrent for torrents.

Those above are the main ones and from there you can add things that make your life easier:

• Prowlarr: sonarr/radar need an indexer to search, instead of configuring them in each software this allows you to do it once and then sync across the other apps

• Overseerr/Jellyseerr: if you want a nicer frontend to search and make download requests instead of doing so in radar/sonarr.

• Recycler/Notifier/Configarr (all do roughly the same): sonarr/radarr allow you to configure specific profiles to score the quality of downloads so you can get them in the format you desire (e.g. so you want 1080p or 4k, HDR yes or no). These allow you to sync custom formats with sonarr/radarr that others like trash-guides have developed.

• Tdarr: if you would like to reencode and compress movies to save space this allows you to do so in an automated way. Although you usually I’d imagine it might be easier to just setup a better profile in sonarr/radarr and download the desired version (should you e.g. want x265 encoded versions)

I don’t have one myself, so I can’t really recommend a specific model from experience. There are many available, but I’ve e.g. seen beelink mentioned a few times. Maybe someone else here is running one and can give some recommendations?

If you are facing availability issues I’d to the reverse and rather then asking for recommendations look at what’s available and then do a quick search or ask about it (e.g. if someone has already used it with whatever Linux distro you plan on using). Should you have access to something like AliExpress then there are plenty of options.

Maybe a mini PC with a N100 might be worth a look? Especially when factoring in running costs over it’s lifetime

No need for special equipment, when it is possible using wifi see this article for example.