The SOC is a set of guidelines that professionals choose to adhere to. So for example, here in the UK you could go to a public health gender clininc, and fall under their stricter, modified SOC, or you could go to a private practitioner that has decided to practice by a more flexible standard. Basically, it boils down to you asking every therapist you try by which SOC they practice.
You shouldn't have problems getting onto anti-androgens. Just keep in mind that you do need to replace the hormones you are blocking with something else eventually, or you run the risk of osteoporosis, heart-problems and other health concerns. I was on anti-androgens for about a year before starting oestrogen about 6 weeks ago now. The main reason I started and didn't delay until going home to South Africa in August besides the obvious (I WANNA TRANSITION!!!) was because of concerns over bone-density.
Hope it helps,
~Simone.