Although you mentioned your after a website, i just have to ask...have you checked your LFS?
I would imagine that ordering the wood online could cost your an arm and a leg in shipping it, depending on how big it is. An advantage of going to a LFS is that you can choose the wood yourself: nod: and despite the slightly higher price, you get to take it home right away!
Same goes for the Java Moss, however, if your LFS doesn’t have any, ordering online is an option considering the amount of online retailers.