If you're good and comfortable with house wiring, I've found the best way to build a cabinet is to install a powerstrip internally then open it and extend the switch to a 20a 120v hard-mounted external switch, like the original cabinets had. In fact, you can actually use the original switches to be honest, they ran on 120v systems. I normally replace them just for reliability sake.
Once you do this, everything is left as "wake on power", or left switched "ON". Even the Pi can work this way, but will need a proper shutdown process to turn it off. Everything else in the cabinet will remain off when power is off, then immediately turn on when the main power strip is energized (Lights, LEDs, Audio, Monitor.. etc... just like an original cabinet did. When I build a cabinet, my goal is Old School.. I like it all on at once, and ready to play...all discrete and hidden so you can't tell it's a PC or modern electronics.
Again, not saying to do this, but I am very comfortable designing and working with power, so it's not an issue for me.