Surgery will knock off 50+ pounds over the first year. But regain IS possible, so you would forever have to be vigilant as to your calories in/out post-op as well.
One thing most of us didn't know before starting this process.. (but we are learning now..):
Exercise has relatively little to do with weight loss.. it's all about what you eat. In fact, after a minimal level of exercise that is enough to make you strong and maintain your lean body mass (muscles and bones, etc)... exercise is actually counter-productive because it makes you HUNGRY (one of your biggest complaints).
If I could guarantee you would heal up from surgery without a problem, and live your life, forever healthy.. then I'd say it was a good option, and you should run out and do it tomorrow. The problem is that that isn't necessarily gonna be the case. Complications can and do happen, and some can be life altering, or even life-ending. It would be a shame for you to take that risk, when your body is likely just screaming for balance.
Go to the gym twice a week to do weights. Walk 3 miles every day. That's it. Any more exercise isn't really needed.
Check into getting your RMR/BMR tested, then use that information as a baseline for figuring out how many calories to eat.
The thing is, that these suggestions are the same as we all have to do after surgery anyway.. you should just try them first.