I have made one using that style rack. It worked very well. I trimmed the legs a bit so it would sit flush and I could use lidless tubs. I put peg board on the top to allow ventilation. I am not currently using the rack but when I was I loved it. Sorry I don't have pics at the moment and I deleted them from photobucket a while ago so my thread with it wont display the pics.
instead of using pegboard, i can just drill holes in the lid? as well as around the tub right? and does it matter if the shelf is ventilated or not? or plastic or metal?
i use one to hold a few crestie tanks on top, a 20L tank on one shelf, my 2 small corns under that in sterilite totes, and then roaches and mealworms on last shelf.