Some 2 and 3 "stackers", this is what we use exclusively. They are easy to clean and you can throw them in the back of a truck and power clean them at a car wash. They are easy to make, and the prices are reasonable if you prefer to buy them.
We make them using 1" X 2" rabbit wire for the top and sides and 1/2" X 1/2" hardware cloth for the floor, (NEVER use hardware cloth, make sure it is welded wire! Hardware cloth will shred and will last about 10 minutes) we use 4 legs, 2 pan slide, a drop pan, and a latch for the door.
