Welcome to 3FC.
So when is your surgery scheduled? Or do you plan on a consultation after you lose your weight?
Just to give you an approx. time line, my sister is your height, and started out considerabley heavier than you, and has just lost 40 pounds...she has worked
very hard and has stayed on her plan 99.9% of the time. It has taken her 5 months. With you being 40 pounds lighter than she is NOW, I would suspect it will take around 6 months for you to lose 40 pounds and be healthy enough for surgery. Good Luck!
ETA
(Oh BTW: She had a boob job last time she lost weight...but gained it all back plus more. Now she has really REALLY big boobs!

)