Can't talk about AMD but I'm on NVIDIA and I always followed https://wiki.debian.org/NvidiaGraphicsDrivers and never had issues others seem to be having. I typically hear good things about AMD GPU support, on Debian and elsewhere so I'm surprised.

Now in practice IMHO GPU support doesn't matter much for NAS, as you're probably going headless (no monitor, mouse or keyboard). You probably though do want GPU instruction set support for transcoding but here again can't advise for this brand of GPU. It should just be relying on e.g. https://trac.ffmpeg.org/wiki/Hardware/AMF

Finally I'm a Debian user and I'm quite familiar with setting it up, locally on remotely. I also made ISOs for RPi based on Raspbian so this post made me realize I never (at least I don't remember) installed Debian headlessly, by that I mean booting on a computer with no OS all the way to getting a working ssh connection established on LAN or WiFi. I relied on Imager for RPi configuration or making my own ISO via a microSD card (using dd) but it made me curious about preseeding wiki.debian.org/DebianInstaller/Preseed so I might tinker with it via QEMU. Advices welcomed.

PS: based on few other comments, consider minidlna over more complex setups. Consider Wireguard over tailscale (or at least headscale for a version relying solely on your infrastructure) with e.g. wg-easy if you want to manage everything without 3rd parties.