What country do you live in? I think it's much easier (and cheaper) not to deal with transshippers on aquabid if it can be avoided, which is why I don't even look at Thai fish. There are some beauties for sure, but I don't want to fall in love with a fish that will cost me at least $20, plus at least $30 in shipping! I live in the U.S., so I try to only look at American breeders (like Hopdiggity and Martinismommy, for example). That's just me personally; if you fall in love with a fish from overseas don't let me discourage you, just know that you'll have to spend a lot of extra money for shipping a betta overseas. Also Thai fish need to be very carefully acclimated because the water is so different. But like I said, if you find an overseas fish you really love, and the breeder has good reviews, by all means get the fish you want! Just read up on how to acclimate a Thai fish first; there was a thread recently, I'm sure you can find it easily if you use the search feature.
You can also check your local Petcos...they get a nice variety of tail types (including HM) and you can get some really great fish there; just look around for one with good variety, and that seems to take good care of their fish. You can also try local fish stores and local pet shops, you never know what they'll carry! Some local shops can even special order certain tail types and/or colors, so it never hurts to ask.