I located both the ac and dc panels in an overhead rooflocker because I want to have as much as possible at eye level. Here is a picture with a hole where the 12v
panel will go, and another with the 12v
panel partially installed.
All the dc wiring is in conduit, and all the ac is MC armored.
I like the idea of a fold down panel. I terminated all my ac wires with marine quality cable because it's very flexible. My panel is pull-out rather than fold down, but I would definitely go with stranded & tinned marine cable if you want to access behind the panel.
I'll look forward to seeing what you do with the 4/0 cable.