Recently picked up an Atomic keyboard from OLKB. They only had the plate and PCB available, no cases. My plan is to get my own case cut from Acrylic or something. I used 65g R3 Zealios and the current key caps are Devlin L from my Cherry MX Board 3.0 with some SP G20s blanks filling in the remaining keys. I went with a full grid layout so I can easily reassign my key mappings without having to resolder if I change my mind. I'm pretty happy with the layout except the Esc key. It's weird having it on the right side. But I found having the number keys offset to the left is more natural or at least closer to what I'm used to. I also have an NPKC 27 switch tester that I hacked up a bit as my numpad above the keyboard.
Since I don't have a case yet, I cut a piece of foam to set the keyboard down on for now. It actually works pretty well. I could probably just leave it like this if I wanted to and didn't move it around much. You can kind of see the difference between the Devlin L and SP G20s here. The Devlin sit a little lower on the switch.
I've read about people putting some foam between the PCB and the case to help reduce vibrations in the case. One idea I had was to put some foam between the PCB and the backplate as well. So I cut some strips of foam and placed them in the gap between the switches.
Not sure if it really makes much difference. Since I don't have a case, the soft foam I have the keyboard sitting on already makes for a pretty damped sound. But it wasn't too much work and it won't hurt. The only issue was that I had to hold the PCB down when soldering to make sure that it didn't lift up and leave a gap between the switches and the PCB.