How old are you? Chin implants in themselves can be an excellent way to re-define the area. if it has lost shape due to aging. I know of a patient that was given one in lieu of a neck lift. Reportedly the results turned out well, but I have yet to see him since surgery so I cannot personally comment on it.
I would also be curious to know which surgeon(s) you are considering. Undoubtedly you will want to go with one that specializes in facial work. Don't try asking a surgeon that only does body lipo do to your neck