I know that in New Hyde Park there's a place that deals in arcade machines...  A friend lives near the corner of Jericho Turnpike and 12th (Street?  Avenue?) and we took a short walk from there to check the place out, but it was closed.  I could find the exact address, if you'd like.  Email me at jstookey@yahoo.com if you're interested.  While window shopping, it looked like they had a bunch of really nice cabinets in there (which says to me they're probably expensive), but maybe they also have some machines that aren't showcased, like cocktail cabinets.  Who knows?
I would also suggest building your own.  Preserve the real machines that are out there.  It probably wouldn't be too terribly tough to put some planks together to make a wooden box that would house a better machine than some little pacman cocktail cabinet.