If you are looking for 180 not 140 stand you might able to contact the company for it but odds are low. If they don't sell it in stores they probably don't have extra produced and they'd end up stuck with a 181 that has no stand instead of you. I would just build a wood stand. Setting it up with castors might be a little complicated but otherwise it's just a box with 4 pieces on top, 4 pieces on bottom, 4 legs, and a piece that spans the bottom for stability. Lowes here will even cut the wood to the correct size for you. If your chins will not be loose around the cage you can coat it in polyurethane or enamel for water proof protection and then it will wipe clean and sterilize just like plastic. That's how we build our hedgehog breeding cages since they don't chew.
We also have a 142 with no stand sitting on a dog crate. Whatever works.