This is only to be done if absolutely necessary, I do remember one occasion at the pet store I worked at we ordered a shipment of 10 new baby ball pythons, they were to arrive on a Thursday and that Wednesday morning a customer was to arrive and take 10 snakes he had already put a 30% deposit on, leaving each new baby their own cage. Well the customer had a serious emergency come up and had to go out of town for a week (we decided to hold them since he was a repeat customer and we knew he probably was not just BSing us). All I could do Wednesday evening was grab a used 40-gallon tank off the clearance rack, deck it out with 10 hides, two hot spots, and everything else. I was afraid they would take longer to adjust because of this but no they actually took some rat pups about 6 hours after coming in the mail and ate again one week later right before being separated.
Seeing as how you want a rack I am going to assume you plan on building a small/large colony. The minimum tub size I use for anything terrestial is 30-32qts with cypress/coconut coir mixture as bedding, a hot spot via cable/pad, one hide cave, I also create other hides by using fake plants, and finally an 8oz deli cup as a water bowl. Many people use much smaller tubs for hatchlings honestly I find all mine to enjoy a bit of space, my 2013 pastel is in a 106qt right now due to some tubs not arriving on time (they are here today thank goodness) and is doing great. These are the tub sizes I use for young python regius and reticulatus...
http://www.amazon.com/Sterilite-32-Q...age+containers
http://www.amazon.com/Sterilite-1889...age+containers