I can't vouch for them personally but we have a local place that people seem happy with. Northcoast Custom Arcades https://www.mameroom.com/webstore_home.asp has a ton of options from diy kits to completely finished machines. Tons of options as well, upright, cocktail, pedestal, custom graphics etc... It ain't cheap but if they're looking for a more hands off experience it might be worth checking out.