From your photograph and your description, you have not only an umbilical hernia, but also fairly broad diastasis (stretching and widening) of your rectus sheath (the fascia or "gristle" that envelops the rectus or 6-pack muscles) that extends well above your umbilicus. You also have enough loose skin (or WILL, once the diastasis is repaired) that both endoscopic and mini tummy tucks will fail to adequately address.
I must respectfully state that yours is not even a "borderline" case or a "close call!" You require a full tummy tuck for the best cosmetic result! I agree with Dr. Rand's assessment of the other two doctors' advice. Sometimes it's a case of trying to say what they think you want to hear, but it could also be a case of "If all you have is a hammer, then everything is a nail." The doctor suggesting a mini may not be a fully-trained ABPS-certified plastic surgeon, and capable or comfortable only with a mini (perhaps this is not even a hospital or accredited surgical center case?), and the doctor suggesting an endoscopic approach may be trying to accomplish too much with a limited-application technique (but probably is a fully-qualified plastic surgeon, perhaps a younger one?) Either way, I believe you will waste money and be quite disappointed with anything less than a full tummy tuck with hernia repair and diastasis plication (muscle repair or fascial repair). Get another consultation or two if you have any doubts. Best wishes!