Homelab n00b looking for hardware and OS advice

Hi everyone!

I saw this video yesterday (https://youtu.be/vjDoQA4C22c) showing a nice custom homelab build that’s a lot of bang for the buck, and I felt that it was time to replace my tired old Asustor NAS with something more fun. But I would like your wise advice and experience. 😊

Purpose:

Torrentstation - automated with Sonarr, Radarr, Prowlarr via qbittorrent and through Wireguard VPN.
Media server - I am currently running Plex Media Server on the NAS, but it sometimes struggles. I can imagine moving over to Jellyfin.
File backup - standard, photos, etc. Local backup mirrored to cloud service.
Other bits and pieces such as Home Assistant, AdGuard/PiHole, tinkering with some Linux stuff [insert your best tip here]. 😀

In the video, he builds his own NAS based on an n5105 NAS motherboard. I’m looking at the new topton i3-n305 mini PC maybe, which is said to have slightly better performance (?). Both seem to be energy-efficient, quiet and very good value for money.

But I am open to other suggestions. Preferably as small a form factor as possible as I would prefer to hide it away in the small junction box cabinet or in the TV cabinet.

I’ve also been looking at an Intel NUC (i5 or something) and just throwing in my two NAS HDDs into a two disk Raid enclosure and connecting via USB-C. Yes/no?

Then OS and software wise. What should be the base on this thing? Ubuntu? As I mentioned I want to set up qBittorrent, Sonarr and Radarr like I have to today. Get them to work downloading the media I want and then run a Plex or Jellyfin server on the machine simultaneously that my Nvidia Shield Pro can connect to and run the media to my TV.

Thank you in advance! 😊