This is an awesome idea! I like the mock-ups thus far too. With custom layouts/themes it'll really pop. You could use the Fallout "Please Stand By" for the loading screen etc. Also, depending on how crazy you want to go, there are a lot of "steam-punk"-type custom ideas that I've seen around that you could add to the cabinet for aesthetics.
I think the biggest thing will be your control panel - you'll really want to hammer that design down. FWIW, personally I'm not sold on the billiard ball as it doesn't cry "Fallout" (though it does match the old-thyme look). You could use the "O with the lightning bolt in it" from "Fallout", or the nuclear fallout symbol (if you chose not to use them for the buttons), or even the orange glow of the pipboy buttons as just a few that come readily to mind.
I'll definitely be tracking this project as it seems like a great one! Keep up posted!