I would try the Cornell-Weill center for Peripheral Neuropathy in New York, or the Neuropathy Center at Massachusetts General in Boston, or Jacksonville Shands in Jacksonville Florida first (probably in that order).
Then perhaps the Johns Hopkins neurology department in Baltimore.

All would be shorter trips, as well.

In the midwest, my first choice would be the Jack Miller Center in Chicago, followed by the Washington University Neuromuscular Center in St.Louis.

All of these have the virtue of being dedicated to neuropathy research and treatment.