There's a pretty active Michigan Betta club that does shows every year. There is also the Midwest Betta club which is VERY active online.
You can get in touch with the heads of those chapters by going to www.ibcbettas.org/pages
and looking under "domestic chapters" and sending an email to the contact person.
Also you can join the IBC and get in touch with US breeders all over and see if anyone is breeding what you're looking for and would be willing to sell you some pairs. Most IBC breeders do not advertise their fish but are happy to get some pairs to someone looking to get a line started.