Answer: The simplest approach would be to work with a local professional garden designer and/or professionally trained and degreed landscape architect who could help you plan your garden and source the materials you need to install it. Another way to go about it would be to use google to search for "Japanese style garden supplies" and look for mail order suppliers. As far as rocks and sand, your landscape supply yards and/or landscapers should be able to supply those locally; shipping costs would be prohibitive on these heavy weight materials. If you need design ideas, your local librarian should be able to show you books with photos of Japanese style gardens to use as inspiration for your own. I hope this helps you get started on your project.
Q&A Library Searching Tips