I always laugh a little when some one uses "ball python" and "natural looking enclosue" in the same post. Honestly, unless you plan on creating a termite mound in the cage, it won't be natural for the snake. Lets not lose perspective on the fact that we build these "natural" environments for ourselves, not the snakes.
I urge you to keep cleaning in mind for each item you add to the tank. Ask yourself how hard it's gonna be to clean poop and urates off of anything you put in there, because sooner or later you'll need to do just that.