What you are looking to build is a JAMMA cab that you can swap different games into.
Your best bet is to look around your area and in your yellow pages, etc and get to know a few Operators and/or collectors. Especially if you aren't in a rush to get going, you'll be able to find a JAMMA cab for dirt cheap. Unless you are in an area with very few machines, you'll be able to pick up something like a 25" JAMMA cab for probably $100.
Once you have a JAMMA cab, you can add games as you see fit. Any JAMMA board will fit right in, and assuming you have the controls for it, you'll be up and running in no time. If its a JAMMA+ game (which means its has more buttons than the JAMMA standard), you'll need some kick harnesses (extra cables for the extra controls) to hook up the other controls. You'll also need to have a control panel that can accept the new controls of course.
Older classics like Pacman, Frogger, etc aren't JAMMA, but you can get a JAMMA adapter for them and make them pretty much plug-and-play.
That is, IMHO, the easiest way to attack this for you. Get a working JAMMA cab, even if you don't like the game that's in it... or if it doesn't have a game at all... then just build up your PCB collection as fast/slow as you want. You can add new art to the cab if you wanted, a new control panel, etc etc... and IMO, its a lot easier to start with an original cab than building your own from scratch.
Just don't butcher a classic cab... we don't like that around here

EDIT: I also forgot to mention: If you do wind up wanting a MAME machine, you can use a JPAC and just plug that into the JAMMA harness in your cab. That way you can add your computer to the cab just like you would a different game board.