A Nylabone product shouldn't be hard to track down, even if the specific one is a bit tricky. That one I have never seen before, but if I were you I'd give Nylabone a call directly to see if any online retailers have picked it up, next step is distributors for stores in your area.
It's a convenient crate, but not very durable. Unlike wire crates, where if they get bent you can just bend them back, it seems easy to cause a fatal break in one of these crates. They're tricky to fold up, too.
Petsmart used to have them a few years ago, but I don't think they do now. Good luck!