Is a sliding genioplasty sufficient? (Photo)

Thanks for your question and for the photo.
It looks like you have put a significant amount of time (and money) into correcting you bite, and your teeth come together nicely.  Since this is the case, I would not recommend jaw surgery, such as a sagittal split.  This would bring the whole jaw forward and make your lower teeth jut out way ahead of your top teeth.  
A genioplasty is a good solution.  It won't change the bite that you've established, but it give your chin projection.  The benefit of a sliding genioplasty is you can increase projection in the horizontal and vertical direction.  A very big advancement may need a bone graft, but big movement are definitely possible!
Meet with a craniofacial surgeon in person to discuss your options.
Best of luck
Dr Rodman