Thanks, Im glad you like it so far!
As for the stones - yes, you may. I bought them from a swedish zoo dealer called Djurmagazinet, and they get their aquariumstuff from a gross dealer called Akvarieteknik (akvarieteknik.se). The stones are also called Honeycomb rock.
I think moss sounds interesting, i've always liked it but the only moss I've seen here is Java, which I for some reason never get to grow well.. might be the water here. I like doing things low tech, any thought on how to get it to spread like a carpet? I think it would make for a nice jungle look .
As for tall plants, I have some coming up soon