There is no good answer for you problem. On this one picture, it appears you have some loose skin just in the immediate periumbilical region, about 2 inches around the belly button, then you have some excess subcutaneous fat, another 4 inches. It appears to me, you have some rectus abdominis muscle weakness in the area below the umbilicus.
If you want to obtain the best result, accepting a longer scar, then abdominoplasty will be the best, but you may need a short vertical scar in the pubis area. An umbilicoplasty will improve the area around the belly botton but will not address the muscle weakness. Some liposuction may improve the appeareance of the bulging around the skin laxity, then a purse string closure may decrease the size of the umbilicus. A good physical exam will provide more data to formulate the best surgical plan.
