I think it's an excellent idea. I saw the same things that you did in your searches, psiflow; it's either buy from petco (cuz petsmart has horrible selection of bettas here!) or try online, but every site I went to said they weren't selling at present. This was before I found this forum, of course. I would be very willing to buy from your site, knowing that I was getting a fish from a small breeder here in the USA. It would be nice to be able to purchase a good or excellent quality betta with coloring and/or fin type that is different, maybe something I've only seen in a book or on the internet.
PS: I understand the kind of site/business/service that you are contemplating and it's a grand idea!
PSS: sorry about run on sentences and grammar issues...it's late.