I am not sure what the brand is. My mom gave it to me. Its just the normal exercise pens like you see people use at dog shows for their puppies and/or their pets to use the bathroom. It seems like you'll always see them outside of RV's.
I've seen the exercise pens at both Petco and Petsmart. I believe they have the taller ones in their store, but i am not 100% sure. They may have them at walmart or target as well.
Here is the basic style of exercise pen that i am talking about....
https://www.google.com/#q=dog+exerci...06062456331459
Anyways...here is place that's selling a cover and/or mat underneath. If your pup could posibly get out, this would keep them in and they still have lots of room to roam.
http://www.petsouterspace.com/buy/ex...POS-EP-800-10P
Here's a big crate....
http://www.petsouterspace.com/buy/48...crate/POS-CR48
If you get a big crate, you can't add on...and on top of that, you'll have to clean out the potty out of the bottom tray. I would think the other one is easier when it comes to cleaning poo and pee.
I know the one store is in Australia so it wouldn't be economical to ship from there, but there's got to be similar stuff in the US. I like that you can buy panels and add onto the pen and I love the roof and floor idea!!