3D printing is very popular, available and cheap opportunity how to make a lot of cases specialy for your needs.
You can make your own NAS or media centre with single-board computers like Raspberry Pi, Orange Pi or Banana Pi.
If you don’t want to set Linux OS for this using, you can use e.g. https://www.openmediavault.org/. OS which is based on Debian.
3D Cases for Raspberry Pi 2/3

Link to 3D project: https://www.thingiverse.com/thing:2407893

Link to 3D project: https://www.thingiverse.com/thing:702489
 
Link to 3D project: https://www.thingiverse.com/thing:1357022

Link to 3D project: https://www.thingiverse.com/thing:655304
 
Link to 3D project: https://www.thingiverse.com/thing:2094601
3D Cases for Orange Pi PC

Link to 3D project: https://www.thingiverse.com/thing:2468854
3D Cases for Banana Pi Pro

Link to 3D project: https://www.thingiverse.com/thing:1105052
 
Link to 3D project: https://www.thingiverse.com/thing:2090120
 
Link to 3D project: https://www.thingiverse.com/thing:2676179






