@NiwlCraft If ARM is not a strict requirement, I can highly recommend the ASRock Intel N100M. Throw in up to 32 GB DDR4 and some storage (M.2 NVMe or SATA) and put it in any Micro ATX case. I have mine in an old server case with a pico PSU for fully fanless operation.
It's powerful enough to run Jellyfin (with hardware encoding), Immich, Homeassistant and a few other things at the same time.
If you ever need more storage, you can add a PCIe card for more SATA.