I use pet food bowls from ikea. If your using a rack they are perfect, I use them for water bowls and hides. Because they are so large they cannot tip over in the rack. They have two sizes, one is perfect up to about 1900g and the small ones are good for hatchlings/young snakes. They are dirt cheap too..
http://www.ikea.com/us/en/catalog/products/90140379
