Some words of encouragement:
I think a SG may be the way to go. Your expectations are very, very realistic. Your lower lip does not sit noticeably behind your upper and you're not looking to change your jaw angles. Sure BSSO +SG would be ideal, but you're one of those cases where SG alone may work very well as well, given your expectations. I would be more concerned about your expectations around the nose job. That lowering of the nostrils that you showed there is very difficult to achieve to that degree.
Have you heard of a surgeon in Cleveland called Guyuron? He's one of the best rhinoplasty surgeons in the world and does a fair bit of sliding genioplasties as well - including complex revisions of both noses and chins. He's a plastic surgeon as well as a craniofacial surgeon, widely published and with a name immediately recognized by any surgeon in the field in US and even overseas. I've seen surgeons mentioning him and putting pictures of themselves with Guyuron on their web sites just to increase their own credibility. I think you could benefit from a consult with him. You can probably do both the nose and the chin for pretty much that preposterous amount in swiss franks that you quoted here for a SG only.
You're lucky you're in US. If only I were in your place. I would never leave US to do a surgery elsewhere, not even Germany which is scientifically and medically more advanced than any other European country.