If you want a good online site to purchase these fabrics, try eQuilter.com. Luana and Paul Rubin there specialize in Asian fabrics, and it seems to me that they have a TON of different ones.
You could contact Back Porch Fabrics in Pacific Grove, CA. Also, Annie Smith, who appeared on an episode of TQS is collecting Japanese fabrics. Her email is: mailto:Annie@simplearts.com. Hope this helps. Judy in Torrance