Perhaps im just a jerk but all im seeing here is a very expensive diskless nas case that i can already buy from aliexpress for an order of magnitude cheaper. I'd be glad if you could change my mind.
There are exceptions of course, but it's not an easy task to find a nice solution that is quiet, vibration damped (easier on spinning disks), good airflow (keep drives cool), nice mini-itx or similar motherboard (ideally with ECC), an expansion port (10G or M.2/U2 cache), etc.
One I've had my eye on is the Fractal Design Node 304.