Although without a doubt you would have a better result after some weight loss, there are circumstances in which the amount of improvement may justify the added risk. By in large, those patients who might benefit have skin overhanging the lower abdomen. (A photo would help surgeons replying to your question.)
Tightening the abdominal wall is not particularly helpful in flattening the abdomen at this weight.
When you ready for an in person consultation, RealSelf has listings of surgeons in your area. You should consider cross referencing the listings from the The American Society of Plastic Surgeons (plasticsurgery dot org). A listing in the ASPS website assures you that your surgeon is not only board certified, but also is a member in good standing of the major plastic surgery organization in the U. S.
Thank you for your question, best wishes.