The best substrate I've used for mine were slate tiles. They got to be a pain though because insects would crawl into the cracks and anytime he had to go to the bathroom it'd be right over where there was a little space between the tiles so it was a pain. Now I use a vinyl flooring that looks like tiles. Just be sure not to get one that is mold resistant or with the adhesive backing because it can give off toxic fumes when heated. For mine I just bought some Velcro strips and attached it along the edges. If you do go with vinyl flooring go for a textured one so the lizard can get a grip on it, otherwise they'll just be sliding around and running in place.
Looks nice! Mine used to love his reptile hammock. Now his cage is wood though...and he's too fat.
