HyunJun is right, there's a BMI range that you have to be in for a surgeon to accept you for this type of surgery. You would have to have a one-on-one consult or attend an information center to find out more information - it may be different for each surgical center.
Since you would have to make the healthy lifestyle changes after a surgery for it to be successful and you may have to start losing weight before a surgery, why not start now and see how far you can get with good nutrition and physical activity alone?