Don't know if you've found anything or not, but 2 places I highly recommend are Craigslist and ebay.
Just be sure to get a key for whatever you buy as that's a problem especially on ebay. Beaver, Northwestern, Oak are my top three suggestions. Just be sure to get the correct toy capsule wheels if you're going to do that. You can convert these pretty easy. My Northwesterns I use 2 gumball heads on a double and put bouncy balls in one side for some of my restaurants like youre wanting to do. I would definitely do gumballs and toys in a restaurant to start off with. I've had super results even in small diners with gum/toys on a double headed machine.