We had one (floor to ceiling) from WM, but it didn't really work well for us. We had an odd ceiling height and we did something to try to make it fit right for our needs... needless to say, in the end, it didn't!
I ended up getting one from ebay actually. It's a good sized one, different levels. I think I spent around $200, which was like 1/2 the asking price at PetSmart store.
Good luck!
Becky