Just buy a FreeNAS mini from IXSystems. It just works. I have had one for 6 years now with no issue. Yes it cost money, but if you can pay for 4x12TB then I assume you can pay for the mini. :)
When I was younger and still an everyday networking guy I had a rack with tons of kit, ran my own DNS, firewall was OpenBSD, etc. Today I have a family and a sr. role at a startup. My network is 100% Ubiquiti, storage is a FreeNAS Mini and every TV has an AppleTV with the same apps and setup. Why because I do not have time to play anymore. Why because if I get killed in a car accident my non-techy wife can understand the tools I left.
https://www.truenas.com/truenas-mini/