HRT its only potentially dangerous. That's not the same as being actually dangerous, and if you have a decent doctor it never will be.
I don't believe estrogen is toxic, it is after all natural to the human body. It would be like saying water is toxic, and can kill you. Which is true from certain point of view, but not very helpful. Women do live longer than men, so perhaps you'll even get that benefit.
Anti-androgens I'm not so sure about, but surgery can fix that.
There are doctors in Thailand for HRT. I've looked into it before when I was thinking of working around the Australian system. I don't recall the details though since I never needed to. There are people on these forums who know who some of them are. I posted something in your other thread. If you get really stuck perhaps I can look again.
For GRS I'd go to Suporn myself, but I can understand the advantage of free with the NHS. Have you checked PAI, or is that out of reach? You're free to do whatever you want there, if you have the money.