Do I need lower back lift or will Vaser / skin tightening suffice? (photo)

Thank you for posting your question here!My answer will be based on the limited information and pictures provided, for a more detailed and personalized plan please discuss with your plastic surgeon in person.
From the limited photos provided it doesn't look like you might have enough skin to merit the extra scar of a body lift , using an energy device like renuvion with some liposuction will likely give you a satisfactory result , that being said , I would encourage yo to discuss with your surgeon as recommendations can change based on the physical exam.
I hope this helps, best of luck!