I'm looking for them, but it's not easy to find them out of USA...Someone may help me?
I'm reasonably sure I've seen mention of this plant in British gardening books. Suggest you also post there on the UK site and ask for addresses. I know there are several specialist seed providers there.
Hope you succeed. Romneya's very nice to have. (Being common-minded, I tend to think the flowers look like poached emu eggs, but I enjoy their company in the garden.)