Breast implants and/or lift. Can I get the smallest possible implant and attain a youthful, perky shape?

I have my first breast enhancement consultation in a couple weeks with a board certified plastic surgeon. But I would Iike to get the communities thoughts on what I need. My main complaint is that I have some sagging from weight loss and a breast reduction 15 years ago. I want to get the smallest implant possible while resulting in a more youthful, perky shape. Will I need a lift in addition to implant? Am I a good candidate for a crescent or donut lift?