Are there reproductory endocrinologists in major cities? Are they all alike?

Yes they are. Yes there are Reproductive Endocrinologists in all major cities in USA I CAN NOT SAY IF THEY ARE ALL ALIKE But you can check their qualifications and expertise on internet.
Yes. Reproductive endocrinologists have done a fellowship after completing a residency, usually in obstetrics and gynecology. They generally specialize in evaluation and management of problems related to fertility and related issues. There generally are specialists in reproductive endocrinology in most cities.