Bard,
I don't know if you have read my extensive ramblings to cathexis, but one thing I listed was this site:
http://www.topsurgery.net/
It will give you a solid foundation when starting the process of looking into top surgery.
I forget to tell you that when you contact your insurance company for providers, you need to ask them to send you information on what is required for them to pay for your surgery. Look on your insurance website for trans health coverage which will also have the information.
Without a doubt both your insurance company and the surgeon will require at least one "letter" from a gender therapist saying that this surgery is medically necessary. Make sure that when you see said therapist that you give them a copy of what your insurance company wants in a letter and what the surgeon you have chosen wants in a letter. This way the therapist will make sure to have all of the information needed for both parties. Otherwise, you will find yourself returning for another letter.
If you don't have a gender therapist you can look for a gender therapist who will meet with you for an evaluation and write a letter for you. Usually this is out of pocket, rather than using insurance. Make sure you also find out the therapist credentials required for the insurance company and surgeon.
Let me know if I can help in any other way.