I couldn't find a good case for the BFO-9000, so I designed my own.
Updated with a minor tweak for the base that ensures both jacks can be installed at the same time.
Here's a link for my layout on Keyboard Layout Editor. PgUp/Dn are Fn + Up/Dn, Home/End are Fn+Left/Right. Obviously this isn't the "perfect" layout, but it gives a left hand numpad which is really useful when one hand is on the mouse and the other is entering numbers (CAD/Excel).
The standoffs on the base are about .5mm shy of touching the pcb, and the idea behind that was to leave room for a rubber washer to help dampen noise, given how loud mechanical keyboards (especially plastic cases) can be.
The case is designed for M3 screws. You can use nuts or not, but it is a personal preference, since the standoffs should have enough grip to hold a screw in.