after a bit of fussing around and hacking up some USB cables and an AV jack, I've got it all stuffed into this project box. life would be a lot easier if I could find some really low clearance USB cords, but for the time being, this totally works.

Also, not pretty, but once I've got a grasp on cutting out the holes for my Gameboy buttons, I'll be replacing the clear plexi with a (maybe laser cut) black piece. And then you won't reall be able to see the ugly innards :