Hi,
It is my understanding that Cinnamomum verum and Cinnamomum zeylanicum are different accepted names of the same species. Correct me if I'm wrong. I believe C. zeylanicum is more commonly accepted, as such, search this one online you'll have more luck. Or just search for Ceylon Cinnamon.
If you don't have any luck on the fruit forum, I've seen plenty for sale online on sites like Etsy which are generally reliable. I personally would go with Logees, they offer 6" starters on their website, and they have a great replacement policy if things are damaged in the mail or don't survive the transition to your garden in ~30 days, something like that.
Best of luck,
Dan