Has anyone come across one that is viable for zone 6b? I know I've asked before, and I've checked places out, some can't ship to the U.S. Tomorrow is her heavenly birthday and I still haven't found a flower. I found a daylily, $47.00 for 1 tuber and they don't ship. I can't believe a nursery in the United States of America doesn't have 1 flower/plant named Madison, besides Jasmine which won't work in my region.

I entered 'Madison' into our plant database search and came up with this list:
https://garden.org/plants/sear...

Thank you, Sue. Is there a way I can find out a nursery where I may buy them?

You would have to do online searches, we don't have anything here with specifically with those functions, except, one thing you can try from here:
open a plant entry and if there are photos, hover your mouse over the thumbnail image (or enlarge it) and see what the caption says. Many of our members have gotten permission from vendors to add their photos here. It will say something like "Photo courtesy of XYZ Nursery". If a vendor is listed, it will have a clickable link to their website (image must be enlarged to see links)