I can personally vouch for our TPT member rainbowfishes; he collects rainbowfish species in the wild; has discovered several new rainbowfish species including Melanotaenia sp “Wapoga Red Laser”; has recently had a rainbowfish species named after him; does great talks for aquarium societies around the U.S. and the world; sells juvies of species on Aquabid; has an awesome fish room in St. Louis (yes 2000 mile away from me); and is genuinely a nice guy. I personally have two of his species in my tanks and they are quality fish - not like the inbred fish coming out of Asia. Do you belong to the Minnesota Aquarium Society there in the Twin Cities?
I'm sorry but all I have are about half a dozen Melanotaenia boesemani 'Lake Aytinjo' that are young adults raised from eggs I got from our TPT member.
rainbowfishes is a hobbyist just like you and me and raises rainbowfish because he loves the species; he has a 'real job' that keeps him busy during the week. If it were me I would PM him and see what he has available or what might be breeding in the near future.
Bob - if you're looking for local fish, there are a handful of people that breed rainbows here locally in the Twin Cities. I will be getting into the game myself very soon with some M. Nigrans, G. Wannamensis, M. Parva, and possibly M. Boesemani (though there are a few people that breed those already). Feel free to shoot me a message and I can try and point you in the right direction.
Alternately, if you're looking for some adults to start out with I have a group of 2M/3F (may actually have another male) of M. Boesemani that I'll be moving to make room for breeders of another species.