Will a Fleur de lis tummy tuck resolve the excess skin issue on my back as well as my tummy?

Thank you  for your awesome question! Your bio is very helpful, however without the benefit of knowing your full health history and an in person exam it's impossible to say for certain. 
  I would recommend you have an in person consultation with a plastic surgeon with these credentials: *Board Certified by the American Board of Plastic Surgery -- The gold star symbol*A member of the ASPS (American Society of Plastic Surgeons) -- The circle symbol*A member of the ASAPS (American Society of Aesthetic Plastic Surgeons) -- the Queen Nefertitti symbol with a Triangle  *On faculty at local plastic surgery teaching program -- in our office we are affiliated with both Duke and UNC schools of plastic surgery.    Feel free to contact our office, it would be our pleasure to answer your questions in person. I hope this is helpful and wish you all the best in your journey.  My sincere best, Brian S. Coan, MD, FACS 

Pictures are always helpful for an assessment otherwise we are speaking in generalities. A tummy tuck, whether traditional or fleur-de-lis, will not take care of the back area. An in-person examination will give the best personalized advice, but it is likely you will need a body lift. You may also need an upper body lift/bra line back lift to take care of the skin of the upper back. Don't expect to turn out like your friend who is 15 years younger than you and may not have lost the same amount of weight and may not have the same skin elasticity properties, or you may be sorely disappointed with the result that is excellent, but not like your friend's. You're only looking to be a better version of yourself not to look like someone else. Best of luck.