probably reading this wrong but isn't any NAS pretty much a server too if media apps are added and configured for media playback?
I've used Syhnology NAS for some time.
that is until I found out it hated bean soup.
there are a few two bay and one single bay storage units.
from $160 to $400.
I like the218 plus $300, and the 718 plus $400, versions.
upgradeable RAM in each. but a faster CPU in the 718, along with two more years warranty and the option for adding on more slave storage later and seeing it all just as the initial unit, and not two different devices.
both can support various RAID arrays. and drives up to 10 TB in each slot/bay..
the cheapest twin bay model makes you use a screwdriver to add drives and runs around $160.
regardless, Add on an ethernet dAC and you are in business... well once you acquire those HD files.
tha Micro Endu interfaces or crosses over from Ethernet to a USB output.
it runs around $500 or less if used.
its power supply is the only issue with its cost. it is reputed to be happy to see upgraded linear PS. those range from $150 to ???
Or did you mean an all in one server & renderer streamer
something you can drop files onto and it has interfaces suitable to connect to any DAC?
these can get pricey.
so far I could flip a coin and take any one of Aurender, Wolf, or lumen. another thread here mentioned Enuus? I think.
that's all I know. Good luck