Plants I'm having trouble finding

So, there are a handful of plants I'd like to get access to seeds or live plants of for which there isn't really an avenue to buy. I'd like to get the correct species, legally & wanted to know if anyone was sure they had access & wanted to get in touch via PM. I'm not including a few species which seem they'd be too much of a pain to bother with.

These include:
Bunchberry (Cornus Canadensis)
(in particular, I need the Eastern Woodland subspecies, not West coast)

Carolina Buckthorn (Frangula Caroliniana)

Eastern Black Huckleberry (Gaylussacia Baccata)

Indian Cucumber (Medeola Virginiana)

American Butterfly Pea (Clitoria Mariana)

American Mountain Ash (Sorbus Americana)

https://www.gardenia.net/plant/cornus-canadensis
This is also available.
https://www.gardenia.net/plant/frangula-caroliniana
It looks like this nursery may have all you want.
I found it from Australia!