Yes i agree your sounds
If the only goal is an open source file server (we call this a SAM-SD, there is a section of the forum just for that) then the most likely recommendations for an OS will be openSuse Tumbleweed or Fedora. CentOS and Ubuntu are fine choices too. FreeBSD is excellent, but less well known.
You make it sound as though the wise choice here would be to install OpenSuse etc direct to the hardware.