You'll need prowlarr for downloading. And a Bittorrent client that works with it (e.g. Ktorrent doesn't).
Then you'll set up radarr/sonarr, and ensure they can talk to prowlarr.
Setting up Plex is straightforward. But I think you do need to make it visible to radarr/sonarr.
It was definitely a pain, but once I had it set up it's been fine.
I have ended up in the past being in a state of “don’t touch anything, it hasn’t broken in 6 months”. Then an update releases and I have to learn everything again. Beats paying 120 a month for whatever streaming services we would need.
https://github.com/aldarisbm/local-k3s-cluster/tree/main/dow...
if you want to have an idea. I used a docker compose approach.
Should be self healing
Sort of. You tell Plex where your directories are for movies and TV shows. All you have to do with Sonarr/Radarr is have them dump the finished downloads into their respective directories.