Organic poppy seeds from reputable sellers other than Hoyts are fine. You can also order dried poppy pods from floral shops - they are not as concentrated in thebaine in my experience. If you are trying to avoid the effects of thebaine avoid the bracteatum species and stems. Some places sell similar plant material that have similar effects as real poppies if they run out, so check what the seeds or pods look like before you buy them if you can to avoid issues.