I was asked to answer your question, but truthfully I don't have any suggestions, I know that Tassie has much stricter quarantine on plants than NSW, and I don't even know about seed imports to NSW from overseas as I always just assumed you couldn't. Are you interested in species Hemerocallis? I imagine they'd come true from seed, unlike the hybrids. If you are into the hybrid daylilies, there are some excellent sellers in Australia, but I'm not sure if they all ship to Tasmania. This company says they do, and they are really great to deal with, I've bought from them several times:
http://www.daylily.com.au/
Sorry I couldn't help with the importing seeds question.
