In case I forget, I can give you the gist (all the extension cords are internal just to get the jacks exposed outside the case):
Main hardware:
HORI Fighting Stick Alpha (Xbox version)
Raspberry Pi Zero 2 W with RetroPie pre-built image on a 32 GB microSD
custom 3D printed port bracket (printing a test of this right now)
I might need to print some internal structures too, but for now I’m just going to jam it all in there.
Power:
Raspberry Pi PiSwitch for power on/off (USB C version for modernness’ sake)
Micro USB male to USB C female adapter
USB C extension cord
Video:
mini HDMI male to HDMI female right-angle adapter
HDMI extension cord
Control (waiting for these to arrive):
USB OTG micro male->USB A female right-angle adapter
Plugable USB splitter cable (for the joystick to plug into internally plus to run an extra jack to the outside for player 2)
USB extension cord
Basically that particular fight stick opens very neatly and includes a decent amount of open space where the Pi Zero can fit along with a big (~7x120mm) slot out the front that the cable goes out. Once I get all the right cables run, it should be easy peasy. The 3D printed part is mostly to keep it from just having three little cable jacks hanging loose out the front, but if you’re not a neat freak, you can get it done with 2-3 online orders and an afternoon.