Betsi, I checked out the ingredients on a package of organic brown rice pasta at the supermarket (I can't remember the brand), and the only ingredients were brown rice flour and water, which I would think are OK? I could be wrong, but I thought brown rice flour was just ground brown rice?
This is interesting enough to find more information about it.
On the other hand, I would save the shiratake noodles for Phase 2, since they contain yam flour, and yams aren't allowed in Phase 1.