Cindy,
Are you hoping to stay close to home?
If you are near Boston, the Dana-Farber Cancer Institute has a good reputation for
pediatric transplants and is known for expertise with bone marrow failure diseases.
Also well-regarded for expertise (although I don't know about their pediatric programs): the Brigham and Women's Hospital, and the Tufts University School of Medicine, in Boston, and the University of Massachusetts Memorial Medical Center, in Worcester.