If you want relatively small low-power box with ECC, checkout Asustor AS6804T. It is nominally a NAS but really you can use it for anything you want, it is just an x86-64 server with some disk bays. You also get nice 2x10GbE, which is rare with these minipcs

If it had a a few more cores, something like this would make for a great node in a distributed system like k8s or ceph for a homelab. At the asking price, however, one could also cross shop an HP micro server gen11.