Well I ordered my control parts today! I found this awesome Aussie site that sells not only the buttons and joysticks needed, but also a Keyboard Emulator to plug them all into! It means that once they are connected, all I need to do is go into the Emulator and map the buttons or directions to specific keys as the Raspberry Pi will see it as a Keyboard! This is awesome and completely solves my controller issue. I was going to buy a wired Xbox 360 controller and then solder the connections, but that isn’t really as elegant and as easy as I wanted for this build and this keyboard emulator will work perfectly! Now I just have to wait for it to arrive.
Meanwhile, I am considering which control panel layout I want. I will have the joystick, 8 buttons for in game actions, a Player 1 button and a Coin button. The P1 and Coin buttons will sit on the side or back depensing on how I build my Cabinet, but I am unsure how to array the joystick and 8 buttons. This website has a lot of layouts that I will decide on and then print so that I can mark the drilling locations on my Cabinet. That will make it so much easier to be precise.
Next step is to copy the Linux install with the Emulators to my Raspberry Pi’s SD Card and boot it up using a regular keyboard to test out how the device performs and how easy it is to bind the keys.