You can talk to your doctor that you plan to do both SRS and FFS, and tell them your anesthesia issue, may be they can give you a good advise. But so far I know it doesn't matter which one you do first.
In my opinion, after SRS you body will develop more feminine look including your face, and it could take two year of developments after srs. And most girl I see they lose weight after srs too. And you staying in Thailand for 6 months so, I think better get srs first and you have more recover time for srs, where FFS might require shorter period of recovering time. Good Luck.