You appear to be a good candidate for a geiniplasty but you may also benefit from a chin implant which is simpler. If yoiu have lip incompetence, it usually improves, but cold persist. Some of this depends if you have maxillary excess (gummy smile). In my ecperience, most lip incompetence improves with chin implant or genioplasty, but if it does not, Botox can help.
Joe Niamtu, III DMD
Cosmetic Facial Surgery
I do not believe vertical lengthening is needed in your case. Obviously, a surgeon who performs a lot of one particular surgery, would have less complications, including ptosis. Lip incompetence in my opinion is best resolved with jaw surgery.
You have a longer facial development pattern which leads to the lip 'incompetence ' and the smaller chin projection. The OMS will do a sliding genioplasty to advance the chin but also " shorten"" the facial height. This also allows better lip posture so the lip does not protrude ahead of the chin point and it enhances the overall lip balance with the upper lip. You could also discuss jawline augmentation or ramal implants depending upon how narrow your face appears from the front .