You appear to be a great candidate for a tummy tuck. You may also benefit from liposuction of the flanks but that needs to be examined by a board certified plastic surgeon like Dr. Andrew Lofman
Of course we have a procedure for you! You're an excellent candidate for a tummy tuck. This will remove most of the stretch marks. I say most because the stretch marks above the belly button will remain - although at least they will be pulled tight and look markedly different. You should have an overall great result given your current figure.
There are different severities of gynecomastia. Ultrasonic liposuction alone can improve most of the mild cases. A combination of ULtrasonic Liposuction and direct excision with an incision half way around the areola will help with the moderate to severe cases. The most severe cases may require complete excision with a free nipple graft. You need to be evaluated first by a plastic surgeon to determine which is right for you.
After children it is very common for women to have sagging breasts (ptosis). Often, an implant and breast lift combination is required. However, the only way to know for sure is by examination. There are plenty of times when an implant alone or a breast lift alone will suffice.