Wow, those are really cool! I'm looking to do the same but I was thinking of maybe http://www.txtr-lite.com/ which came recommended from another member.
There is a Minor Imperfections area to purchase from. Just a thought. I'm still thinking about it myself! I really like what you found though too! Hmmm lol
Just be careful, anything porous is going to house bacteria and what not and with the amount of water we mist our chameleons with, it will grow fast.
I am going to set up a couple of vivariums here in the next month and have been looking at finding a good background that won't have issues. I imagine those wood ones are going to be a nightmare to clean.
It is possible to seal them with some sort of spray, so they are easier to clean?