City Beautiful Carpentry: Soho Penthouse Roof Deck - Great decking - this sort of deck can be custom built easily.
deck (via Copenhagen Penthouse Interior by Norm Architects
interesting idea: plant box and belts . Hook together several belts to be large enough to go around if using real leather belts (from thrift store) . these "belts" look more like strap webbing and could be DIY made to size.