The Main Question

I am looking into updating/upgrading my home media server using some old hardware from my main PC, and I would like some advice on Operating Systems. I have used Windows 10 for the life of this server, and I do not know if that would be the best choice for the future.

My main use case is a Plex Media Server with Remote Access and Hardware Acceleration, but I would also like to self-host a few items, including NextCloud and possibly Bitwarden. I have looked into TrueNAS CORE a bit, but I am uncertain how it would handle these Plex features. Regarding Remote Access, Plex says that it requires

64-bit Ubuntu (16.04 or later) or 64-bit Fedora (26 or later) distributions

and that

Compatible FreeBSD servers require Plex Media Server 1.13.9 or newer

Plex also says that other distributions may work with hardware acceleration, but they are not officially supported. They give a list of supported NAS devices, but they do not mention installing TrueNAS on your own hardware.

My experience with Linux kernel OS's is relatively limited. I had to use Ubuntu for university, and I have used ZorinOS and Raspbian/Raspberry Pi OS at various points. I am familiar with the terminal, but I am by no means an expert.

A Few Lists

Why am I considering moving from Windows 10?

• Tired of unstoppable automatic updates causing unexpected downtime
• Interested in potentially less resource-hungry OS's
• Would like to use an OS more suited for a home media server, if possible

What is my current hardware?

• HP Compaq Elite 8300 SFF
• CPU: Intel Core i5-3470
• RAM: 8 GB
• Storage: 500 GB OS Drive, 6 TB Seagate External (STKP6000400)

What is my planned hardware?

• Motherboard: MSI B250M PRO-VD Micro ATX
• CPU: Intel Pentium G4560
• RAM: 8 GB DDR4-2133 (only have 2 RAM slots)
• Storage: 500 GB OS Drive, 1 TB Internal, maybe the old 500 GB Internal, 6 TB Seagate External
• Still need a case and a power supply
  • I will either purchase new ones for my main PC and use those for this, or I will purchase new ones for this purpose.
  • As a note, my current main PC case can fit 3 internal hard drives.

A couple of random points

• The Pentium G4560 has a slightly lower benchmark than the i5-3470. However, it is 5 years newer. Both CPU's support Intel Quick Sync Video. Would the newer G4560 still perform better for Plex despite having slightly lower benchmarks, or would it ultimately be a wash?
• I feel like using the 6 TB Seagate as an Internal drive would allow it access to a more reliable power supply and a faster data connection. Do any of you have experience shucking this model? Would it even be worth it, with the access to a USB 3.1 port that I would have with the planned hardware? A quick search tells me that it may be SMR, but I am already using it as my primary media drive so I am not certain if this would affect shucking any.
• I would very much like a more automated method of backing up specific folders on the 6 TB drive to either the internal drives or my two 2 TB Seagate external drives that I use for backups. On your suggested OS, do you have a preferred software/script for this?