Pinball FX3 buttons? I’m in the process of building my own cabinet and just plan on using FX3 for the time being. How many buttons should I be buying to be able to navigate the menus, etc?

I have an already built PC that I use for emulation on the TV but also use Steam, so I plan on putting this into the cabinet as and when I play. Is there a way to boot and shut down the PC from within FX3’s Cabinet Mode? Or shall I just be looking to load the game up and shut the PC down manually? 

Should I bother with an analogue plunger or stick with a button?

Thanks.