I would skip Gro right off the bat. When a clinic has multiple doctors on site, they are a hair mill. Also, when a clinic starts quoting retention success, I know something is fishy. I mean, if you were in the market for a house and they start quoting numbers, it tells you the same thing. The merits of the house cannot be seen. The merits of the surgical results can't be seen. Always rely upon patient reviews. Also, what they are describing is typically called "yield", not "retention". You're welcome.
Since Thailand is close you to, you should consider Dr. Kongkiat Laorwong of the Absolute Clinic. Excellent pricing, plus they do PRP treatments as a part of the procedure. I would consider Dr. Laorwong an elite Jedi Master, though I've only recently stumbled upon him but admire his skill tremendously. He can work on all ethnicities. His FUE extraction leaves donors looking untouched. He is aggressive with his hairlines. His graft placement is random and nature made. His yield is excellent. But don't take my word for it. Google him, check out his Youtube channel, look at patient reviews, and get yourself a consultation.