Petmate litter pans are great for mice.
http://www.lnt.com/product/litter-pa...d-colors-.html
They are 20 1/4" x 13 5/8" x 3 1/2" high.
This is an awesome size for mice. They are shallow enough to allow the mice easy access to food and water, but spacious enough to allow room for your breeders and little guys.
Vision also make tubs that could be used for mice.
http://visionproducts.us/htm7/tubs.html
They are 18" x 7.5" x 3.5" high.
These are about half the size of the Petmate litter pans, but they could be great if you plan on separating your females when they get pregnant.
There are also an assortment of plastic bus tubs that are used for busing tables in restaurants that could be good for breeding mice as well.