little prince - For people under 18 in Australia (obviously just incase anyone else asks) Dr Hassall will operate on you because it is really up to the doctor to decide whether you are "gillick competent" (pro-tip: no transgender person ever is, but that is a rant for another day haha) and Dr Megan Hassall doesn't see it as in her role to assess whether you are psychologically ready (and I fully agree with her - that is a job for yourself, family, your GP, psychologist, psychiatrist etc.). I called every other Australian surgeon who routinely performs top surgery and she is the only one (although some will operate if you have a court order).
In terms of the USA, I know Dr Medalie and Dr Crane will perform on minors with parental consent. Dr Garramone will not. I think you should get a list of all the surgeons you would consider for top surgery, and just put aside a morning to calling all their offices and asking. That is what I did and I got all the information I needed. I know one guy who had surgery at 15 in the States so it can be done but you may have to travel interstate for a good surgeon willing to operate on you.