I have a home media server (which may or may not host an arr stack) running on a 5 year old i5 NUC withb16Gb RAM and two USB external SSDs for storage.

So far it manages for the household (3 users) perfectly fine.

Think about power consumption of your hardware. If it is supposed to run 24/7 this can add up over a year. The money could be invested in power efficient hardware instead. There are calculators online

My main reasons are sailing the high seas

If this is the goal, then you need to concern yourself with your network first and the computer/server second. You need as much operational control over your home network as you can manage, you need to put this traffic in a separate tunnel from all of your normal network traffic and have it pop up on the public network from a different location. You need to own the modem that links you to your provider’s network, and the router that is the entry/exit point for your network. You need to segregate the thing doing the sailing on its own network segment that doesn’t have direct access to any of your other devices. You can not use the combo modem/router gateway device provided by your ISP. You need to plan your internal network intentionally and understand how, when, and why each device transmits on the network. You should understand your firewall configuration (on your network boundary, not on your PC). You should also get PiHole up and running and start dropping unwanted inbound and outbound traffic.

OpSec first.

Raspberry Pi 4 (with its linux distribution) and an external usb hard drive attached. Install whatever service you want on it. I have Jellyfin and openproject (previously redmine) on it. This mini thingy sits without monitor, keyboard or mouse somewhere next to my router and connected with an ethernet cable. Works flawlessly.

Not really answering the whole question, but you really don’t need a lot. Currently running jellyfin, a blog and some other fun dockers on a raspberry pi (clone), with an external nas though a large USB would do. Start with just “retrieving” movies to your local disk and think what else you need.

• want to access movies between devices? Get some cheap server (I.e some second hand computer) or a NAS
• want to have some snazzy UI? Get jellyfin
• Want to be able to expand storage? Set up some raid configuration or similar.

Good story about overcomplicating things

Start with one thing you want to do, the most important thing.

Enumerate the requirements of that thing (machine to host it on, the kind of OS it requires, network connectivity, etc).

You’re doing what I’ve always heard as “solutioning” - getting overwhelmed with potential solutions before clearly identifying the problem (e.g. Requirements).

Solve that first thing, then move on to the next thing.

Odds are you can get started with something much simpler than jumping feet first into solutions like Proxmox (which has nothing to do with your stated goals, it’s a storage/redundancy/virualization system). Forget about all that - if you eventually come to a point where you need those capabilities, you can deal with it then.

I would start with redundant local data and a cloud backup. Three local drives with data sync’d or mirrored is much easier/cheaper to get going than spending time setting up a NAS that you don’t know you need…yet.

Or, if you know you need a NAS, then start there and get that established, stable first. Then start your sailing efforts. Pretty much all NAS solutions today support some kinds of virtualization/containerization. I don’t recommend Proxmox as your start.

Edit: I’ve run different flavors of Linux on a laptop for this, with an external drive that got sync’d to a second external drive and to a third external on another laptop. That mostly protected me from local/drive/system failures, at least.