I've got one I just put a new board into. It was a Magic Sword game, but I converted it into a 48-in-1 Multicade. It now plays Ms. Pac, Galaga, Frogger, PacMan, Dig Dug, Gyruss, Burgertime, Centipede, Galaxian, Space Invaders and a lot more games. It's really cool. I just ordered the new Mag-Stik Plus joysticks from Ultimarc so I could switch from 4/way (Ms. Pac, Galaga, Pacman, etc..) to 8/way without any disassembly. I wouldn't part with mine for less than $1300.
I also have an original Galaga Upright that I'm considering converting as well.
I've also built a MAME machine in the past that was really cool as well.
If you can find a used Cocktail table with a Jamma Harness then you can build your own. Keep an eye on Ebay!
Cheers,
Brad