Hi SantaMonica: Welcome to the Osteo Board... Sorry for all your problems at such a young age. But it sounds like you found some Drs that are helping you with the hormones and HGH. I wouldn't worry about any stigma with rHGH, your Dr feels you need it and since there's a limited number of meds available for you go for it. I didn't realize there was an age limit on the bisphosphonates. I know most women can't take them till after menopause, but I thought men could. It's a good sign that you don't have any endocrine probs and that they have been checked, since so many people with osteoporosis have secondary causes like thyroid, parathyroid, hormones etc.
Sorry I don't know of any Drs in your area, but is there a particular reason why you want a GP to handle this? I would look for a Endo, Rheumy, or Mineral Metabolism doc at the nearest
Univ Medical Center. I know that HSS has really good orthopedics/neuros, but if your looking for treatment and not any kind of surgery, I would look for the above. If you definitely want an Internal Medicine Dr, I would still look at the nearest Univ Med Center, they have the top docs, who usually also teach so they have to know their stuff

and NY has a lot of good Universities/Medical Centers. I see a Mineral Metabolism Dr (which are hard to find) that's the co-chair of a osteo research center at a Univ Med Center, and they are involved in a lot of research and are willing to see patients on their limited schedule if you have a referral. That doesn't mean all Univ Med Centers require a referral, it's just the one I go to and several others in my area of CA have the same requirement. Another thing is that these Drs would know more about rHGH, since they are probably studying/researching it in some form.
The Drs I mentioned have more education in the field of bone than GP's or Internists do.
Good luck and keep up the good work...
P.S. There are a ton of us who have done all the "right" things to prevent osteoporosis/osteopenia and we still got it (I did in my early 30's) so don't beat yourself up about that, it just happens!! But there are other things that can be checked, and just to give you an example of a few, Celiac, arthritis, Parathyroid probs, bone archetiture probs that follow spinal surgery, and other spinal degenerative probs, but there are many others as well. Do you have degenerative disc disease, stenosis, or spondilolisthesis? I had 7 spinal surgeries/fractures, 6 that failed so I know about architecture probs caused by surgeries.