I built mine around an N150 board off of aliexpress. 6 SATA slots, 4x2.5G ethernet, 2x m.2 slots. Find a cheap second-hand case, a bit of RAM and you're ready to go. It's got hardware transcoding, handles 4K without breaking a sweat. And it consumes 6W!
I'm more inclined to go with N305/N355 myself for the extra compute (more images/containers). But they're a pretty decent option. I setup a "forbidden router" at a friend's using one. Been working great for his home use... proxmox, opnsense for routing, wireguard, pihole, docker-vm running his AP control software, and a trunas scale VM serving a USB hard drive for home backups.
At home, I'm using a 5900H based mini-pc I bought a few years ago and a synology nas.