I can see pursuing a fanless case just for the challenge of it.
If you google "fanless case"
you will get a start on some other options.
One is the HDPLEX H5
Want to build your own quiet and fanless PC? Check out HDPLEX, the leading provider of high quality fanless aluminum pc case which is completely silent, minimalism designed, support latest Intel Kaby Lake and AMD Ryzen CPU upto 95W TDP. HDPLEX also manufactures fanless,highly efficient, and...
hdplex.com
Another is turemetal
https://www.anandtech.com/show/14562/turemetal-fanless-chassis-for-diy-highend-pcs
If, on the other hand, you are looking for a media center case that is quiet,
you can build one that is all but inaudible, and that costs less.
You might look at the G5620, a 65w unit that is quite strong.
The included HD630 graphics might be ok up to a point
https://www.newegg.com/p/N82E16819118090
A cooler with a 120mm fan will be all but inaudible.
If you buy a gold rated seasonic focus of sufficient power, it will not turn on the fan unless it needs to.
Overprovisioning a bit will obviate the need.
Hard drives do make noise.
But for storing video files they are the way to go.
Here is a nice article on the WD options:
WD has a very diverse hard drive product line that can be difficult to decipher at times. In this article we go over the various 3.5inch hard drive lines from WD to help you decide which is right for your system.
www.pugetsystems.com
If you need fans, plan on running them at low speed.
600 rpm is all but inaudible.
Larger fans move more air at lower rpm.
I like the noctua fans, but some others are very good.
Sadly
www.silentpcreview.com no longer seems to be active.
It was a good source for quiet computing.
If you find a case you like, use some silverstone acoustic padding on the case walls to dampen any sound.