I love that double of yours! I'm a huge fan of doubles though, and haven't really seen one that I don't like.
Buying seed is something that I've never done, since I prefer to make my own at this point, but a lot of people buy seed. It is a great way to get genetics from plants you love but are too expensive. I'm not positive about this, but normally, you can register the resulting daylily yourself. It seems like there is a rule that the person's garden where the plant blooms for the first time is the one that has the right to register is. Something like that anyway. Hopefully someone with some brains will come along and explain that a little better!