After lots of research, I settled on a design similar to KC6TYD's design (which is very popular!) and got a TON of inspiration from this guy. I went with a Gator case with space 6-U.
I've decided to include a power supply but eventually will build a separate "power box" with options for battery, solar, and commercial mains.
I've included my FT-991 and FTM-400xDE (yes, the European version which I bought from a silent key). Also included a Jetstream power supply and an MFJ tuner along with a Wires-X controller. I put a 1-U drawer at the bottom and a Power-Pole distribution strip in the back.
Still tweaking but it works well and I am enjoying it!