as a devote bonsai-er...you can do that with just about any species, esp. fast growing, easily graft-able ones like ficus, citrus, apple, maple, and numerous tropicals. I would acutally recommend getting that guy's books as he does explain different grafting techniques to accomplish it. Really, tree sculptures, like bonsai, are not nearly as difficult or as time comsuming as you may have been led to believe. Check out http://www.arborsmith.com/index.html
Give it try!