I collected wild seeds this past fall for pearly everlasting (Anaphalis margaritacea) and a
local species of sweet everlasting aka rabbit tobacco (Pseudognaphalium macounii but I think you are probably referring to Pseudognaphalium obtusifolium). Both are already sown, since they need to cold-stratify, so I can't send you seeds this year, but could send them to you late summer for next year. Otherwise, they are available online.
I didn't collect seeds from bearberry or sweet fern because they're easier to propagate by cuttings/divisions than by seed, I think. I do plan to get both in the spring and try to grow them at home from cuttings, but no big deal if I fail, since I can harvest from them in the wild. I already failed this past year with bearberry. Let it get too crispy and it didn't recover.
Some other good ones for sun that you could grow (depending on your soil) are yarrow, anise hyssop, self-heal, prairie
rose, fireweed, evening primrose. If you have an area with partial shade, especially from the hot afternoon sun,
nettles, lobelia, Solomon's seal, and wild ginger are nice. All of those and the ones you asked about are plants I've collected wild, but as far as growing them myself, I'm just starting to do more of that in recent years, so not a lot of
experience. Yarrow is the easiest thing in the world, though, and so useful. I recommend that one for sure.
I think they're all available from native plant nurseries. Prairie Moon seems to have the widest selection for the upper midwest, and their prices are reasonable.