I would also consider the Animal Plastics CB-70 series, under the "Iris Racks" section. CB-70 rarely have design changes, so you don't have to worry about discontinued or altered tub design. The smallest is 7 high, up to 9 high double-wide (18 CB-70s). They aren't the cheapest, you're still only looking at ~$80 per cage for the 7 high and ~$65 per cage for the biggest.
http://animalplastics.com/