HI drdave,
I would try this list:
Meidi-ya
Meidi-ya has a great selection of imported yummies but charges obscene prices. I am quite sure they have several kinds of good cornmeal.
location:On the north side of Sanjo Street between the Kawaramachi and Kiyamachi Streets)
Fujii Daimaru Department Store (Tavelt)
Tavelt located in the basement of Fujii Daimaru kicks. They offer excellent selection of high quality yummies at quite reasonable prices – the best cost performance in town, I believe. I have never shopped for baking goods but I would think they would stock cornmeal.
location: On the south west corner of Shijo and Teramachi streets intersection.
More here: http://openkyoto.com/kyoto-support/topic/department-stores-in-kyoto-takashimaya-daimaru-and-isetan
Maki Shoten
This small shop is similar to Meidi-ya but I don’t feel like I have been robbed as I am making my way home after shopping. Maki Shoten is located on Higashi-oji Street. I will have to check the exact location. I am not sure if they stock baking goods though.