Hi - I'm a seed collector (harvest and dry my own) but also have a ridiculous 'seed inventory' ... for my regular gardens (perennials: favouring birds, butterflies and pollinators) ... all sorts of native flowers, etc.; plus, I have an extensive Kitchen Garden, and an indoor grow room. I also focus a lot on heirlooms (and love to grow dwarf tomatoes indoors).
I agree, these are excellent:
Baker Creek
Rareseeds.com
Botanical Interests
botanicalinterests.com
Renee's Garden
Reneesgarden.com
They are all reputable sources. I have also purchased through (I will only list companies with whom I have done repeat orders) ...
Mary's Heirloom Seeds:
https://www.marysheirloomseeds...
Forgotten Heirlooms:
https://forgottenheirlooms.com...
MIgardener
https://migardener.com/collect...
Annie's Heirloom Seeds:
https://www.anniesheirloomseed...
Seed Savers Exchange Heirloom Seeds (yes, I'm a member):
https://www.seedsavers.org
Victory Seeds:
https://www.victoryseeds.com/
And for some of the harder to find heirloom perennial flowers as well as herbs, I have also had great success with:
Swallowtail Garden Seeds
https://www.swallowtailgardens...
I have purchased through Park's, but more for supplies than seeds. (Love their Biodomes for seed starting, they can be used over and over.)
And I am addicted to heirloom and specialty tomatoes (last year I planted 64 different varieties... in zone 3, no less). So, particularly for tomatoes / dwarf tomatoes:
Renaissance Farms
https://renaissancefarms.org/
TomatoFest ®
https://www.tomatofest.com/
All of the above are reputable seed companies. I have had excellent success with their seeds.
Hope this is of interest. Good luck with your seeds!
Dianne