Thanks to the helpful hints I got from all you guys, I have started to make design choices, and to acquire some components.
I already have in-hand:3/4" MDF in suffisent quantity (leftover from other furniture, in suffisent quantity (to confirm form plans bellow))
computer: athlon 1700+ w/ wifi card / HDD (I tried a few games and they played great)
monitor: 19inch samsung VGA (tried MAME and it looks great)
midway coin door (used, but very nice for its age)
two plastic coin mecs (modified to accept .984 tokens)
coin bucket (just so there's something to gather them coins...)
8-way joysticks bat-style (twice) (used but great looking)
4-way joysticks ball-top (twice) (used but great looking) those are mecanically restricted
In the mail:a bunch of black buttons + switches (going for a classy black look)
500 japanese .984 tokens (hope the size is as described, or I'll have to further modify the coin mecs)
In the making:homebrewn spinners x2 over a ps2 mouse (got trackball encoder wheels from GGG and large knobs)
3-d model / plans

I decided to make 2 front-facing 4-way CP and one 2-player side CP with 8-way joystick.
I also decided that the side CP would have trackball, while the side CPs would have each a spinner. However, I am trying to make my own.
Here's some sketchup model. I have no credit for this, I only started to use sketchup today, and started from a pacman cocktail model that I modified.

I still have to alter for my monitor to fit in there, this will help planning. The buttons also will have a different (ergonomics round?) layout. This is just to help planing, not final layout.





I am still in the planing phase and in no rush to get that started, I am moving this month...