I use small dishes from china sets. I think they are supposed to be for individual sauce servers. You can also look into chinese shops for dishes for soy sauce. They have some small pet food dishes for rats/gerbils etc. But I find those hard to scrub clean, while my china dishes are smooth and perfect to sanatize. Walmart also carries a cat food dish, small, and ceramic. Those are great for small tubs too.
You might check local thrift style stores first, as I've gotten a stack of 6 of the little ceramic dishes for a buck. Not even chipped!
I'm not a huge breeder though, and they might have something better, or disposable.
Wolfy