Need best pediatric urologist in U.S.

My 12 year old son has reflux to both kidneys from bladder with swollen kidneys. There is only one pediatric urologist in this state and we do not feel comfortable with him. We are willing to travel to any state if we can find a urologist who knows how to handle this before it becomes "life threatening" as it did when he was a baby. The doctor we used then in TX is no longer there.

Note: There is no official subspecialty of "pediatric urology", only urologists who focus their practice on children. In other words, all urologists go through 1 year of training for kids but most see both kids and adults and are not capable of providing the care my son needs. They almost all advertise "pediatric and adult urology". But we need a urologist who has been working with kids only for a number of years. If any moms have had experience in this area, please let me know very soon.
God bless.