It would be helpful if you posted some pictures of what you're trying to do, so people here could better advise you on how to do it. If you're proposing a welded steel understructure, you'd need welding and metal-cutting tools at a minimum. If you're making a mold out of wood, you'll need woodworking tools. If you need to drill holes in your epoxy-granite casting to mount components, that will require special tooling as well. You'll also need some measuring tools to tell you how you're doing.