As far as I know, there are 3 doulas, 3 childbirth ed?, and one lactation consultant in Bangkok.
I was doing private classes but with the best pro-natural hospital offering classes FREE for those using its facilities, there is no interest in private classes. But, the woman teaching the classes probably wouldn't mind having you attend to learn. I can get you her contact information if you'd like.
There is a lot of doula work for the one practicing doula! I'm still on "maternity" leave as my 14mo old twins are still nursing around the clock. I'm hopeing to get pumping going better so I can attend a birth in January. One doula is now on staff to help with lactation at one of the biggest hospitals.
The other doula is the busiest and may like to have someone on call, especially during the holidays. I can get you in contact with her as well.
You can also get involved with the BAMBI
If you're going outside of Bangkok, you won't find much of anything unfortunately. Regardless of what you can see or do, I'd love to meet you and just talk about birth, doula, CBE, whatever!