The problems you're going to run into are the software and the art. Neither MAME or WinCab Jukebox are licensed for commercial use (I've turned down all of the requests I've gotten to include it in cabinets; I didn't realize you were including it in yours). If you can get a resale license from StarROMs and MAME, though, Foley won't have a leg to stand on. I'm pretty sure you don't have a license to use the Nintendo characters in your coctail sideart, since Nintendo is so anti-emulation. The MAME logo is now trademarked by the MAME team and you'll need to get permission for that as well. This is the crux of Foley's argument for unfair competition: he's had to pay royalties and license fees, and you're using these art assets and software without paying for the same licenses and royalties.
Also, as far as the games go, you seem to encourage users to download illegal ROMs in your FAQ. Before any lawyers get involved, you may want to change the language to only point people toward StarROMs for their additional ROM needs.
If you do get an attorney, you're going to need to make sure you're clean on these issues so Foley can't use them against you.
Note that I am not a lawyer, nor do I play one on TV.
--Chris