Sounds like it could be really difficult to maintain. He could injure himself by rubbing his nose on the screen trying to get out. And if the entire room is heated to a specific temperature, then how will you maintain the proper gradient? They have to have a cool area to retreat to, as well as the proper warmth for digestion. All in all, I'd go with the rubbermaid. I've never heard anything good about keeping a snake in a screened cage.