Chin and Jaw Reduction
Chin reduction could be done, but based on you pictures, can only be effectively done by a bony genioplasty approach. What you really need is chin reshaping rather than just pure bone removal. You need some slight horizontal china advancement and significant narrowing. A midline wedge resection bony genioplasty would be able to create that type of chin change. When you say jaw reduction, it is not quite clear based on your pictures as to what areas you mean exactly. I would assume that it would mean jaw angle narrowing but additional pictures would be needed to get a better understanding of what needs to be done. Any chin and jaw reshaping procedure can be combined with rhinoplasty revision and cheek fat grafting. To get an accurate cost estimate of these procedures, you would need to submit a complete set of pictures for analysis and computer imaging.
Altering the shape of the jaw is very possible including the chin. It has to balance with the rest of the face structure but it does appear to be a reasonable approach. Consult a Maxillofacial surgeon