Congratulations on your upcoming surgery! I know you are excited. If you don't want plastic surgery, then the more excercise the better. I am partial to Water aerobics and water walking. You burn the calories and it's easy on the joints when you first start exercising. Hold your stomach in the entire time (easier said than done for me, but I am getting better at it). Buy some water gloves so that when you're in the water and you are working your legs, you can move your arms back and forth (or up and down) and get more resistance so you're working on your arms. Once you're down some, and you think your joints are ready, do more walking, and exercising up in the gym instead of the water. If you're like me, though, you will love the water.
I go to water aerobics and /or water walking 4 nights a week.
Also,make sure that you keep a journal of what you eat. I use Fat Secret - but a lot of folks use My FItness Pal. Both are SmartPhone compatible. You will be surpised how few calories you take in once banded and how many calories you expend. Be sure to eat Protein first, then veggies, then carbs. Small bites. (I am sure you have heard all of this before.)
Best of luck!