Greetings from sunny Texas!
I just (10 minutes ago) arrived home from your beautiful, but snowy state...a day later than planned due to that snow yesterday.
Second opinions are never a bad thing. Most doctors will not offer one, however, without seeing the medical records....biopsy results in this case.
As for treatment, my personal bias would be to at least check out someone in one of those larger areas, as you stated. Not that a urologist/surgeon (if surgery ends up being part of this) in a small town might not be great, but typically specialists in larger areas have more experience....more patients with similar situations.
Regarding the bone scan itself, it is done to determine if cancer has metastasized in the bones. If the results are positive, the suggested course of treatment might be different than if the results are negative, etc. The bone scan itself takes just a few minutes and does not involve any pain or discomfort....just some mental anguish as one waits to learn the results a day or two later.
Even if the bone scan results are negative, it is still possible that spreading may have taken place to the lymph nodes or to the tissues just outside the prostate (the margins as they are called when surgery is done). If the bone scan is positive, then spreading has definitely taken place.
My urologist/surgeon got his medical degree from UW Madison and I like him a lot, but I know nothing about the school/hospital.
Best of luck to you and your husband.