Mimosa hostilis is not being wild harvested, its grown on farms in mexico and south america. There is nothing unsustainable in their farming, the only real concern is the legality of buying it wherever you are. Its things like Virola and B. caapi that might be harvested unsustainably.
If you want to try your hand at growing a source plant here are some suggestions from most cold hardy to most cold intolerant and tropical:
Desmanthus illinoensis (USDA zone 4+)
Desmanthus leptolobus (USDA zone ~6+)
Peganum harmala (USDA zone 6+ or 7+)
Acacia acuminata 'Narrow Phyllode' (USDA zone 8+ or 9+)
Mimosa hostilis (USDA zone 9+)
Psychotria alba (USDA zone 9+, semitropical)
Banisteriopsis caapi (USDA zone 9+, tropical?)
Acacia confusa (USDA zone 9+ or 10, tropical)
Psychotria viridis (USDA zone 10, semitropical?)
I think I remembered those correctly, lol