I'm using a large PC case that was the last of it's kind display model purchased at Fry's Electronics just before they shut down. $80?

It has:

• a glass side
• a decent amount of space for wiring below the "floor"
• a large cutout in the "floor" for a water cooling system
• a tunnel at the top that is PC PSU cross-section

After a bit of Tetris and thought, I installed an 3mm aluminum sheet "mezzanine" on 50mm standoffs over the "floor". This gives

• Enough space between the mezzanine and the glass cover to install the tallest components - the drivers.
• Enough space between the floor and the mezzanine to install one of the three 6A/60V PSUs in the (slightly adjusted) water-cooling cutout.

The other two PSUs fit end-end in the PSU tunnel, screwed to the top of the case.

Around the three drivers there is two strips of DIN rail with the other component (see image).

Seems to work...

The 5V supply is 10A as I want to use it to power the Raspberry PI and monitor too.

Fun fact: the 3mm aluminum sheet has been knocking around since the late 80s, originally a blanking plate for a Sun 3/180 server rack, which I used to make redneck motorcycle panniers out of. (Sun shipped way, way too much hardware for those racks)