Interesting concept.. I think it would be awesome if you could find the right set of old switches and keep the theme retro to the era of the switches you find. But I am not seeing the coolness factor with just regular arcade buttons.. The scripts should be the easiest part..
If you went with a bank of toggles, you could even go so far as to set up where different combinations opened different games, and depending on the math scheme you used, you could technically have hundreds of choices of games that way.. instead of just pressing 1 for game 1, you toggle 1 for game one and hit "go" to exit your current game and launch the new choice.. If you toggle 1, 2, and 5, you get game 25 (or whatever crazy scheme you come up with). Heck, you could make it binary and half the fun would be trying to figure out the binary sequence for the game you are thinking of playing.. 4 toggles could do 16 different games.. OR, do a NASA theme, make them all safety toggles, and have a "LAUNCH" button that sets off a countdown with lighting and sound effects, then launches into the game you chose with your combination of toggles..