I googled and found an article from several years ago that says at Johns Hopkins, "the rate at which overweight, severely obese, and morbidly obese patients are listed and receive transplants is much higher than the national average. As a result, the waiting times for obese patients are not significantly different." It sounds like they have some experience working with patients of your size.
http://www.hopkinsmedicine.org/news/media/releases/obese_patients_wait_longer_for_kidney_transplants_research_suggestsSo I'd start with Johns Hopkins and the doctor they quote, Dorry Segev, who sounds sympathetic. “Being overweight should not be a disqualifying and discriminating factor against these patients,” Segev says. Per his profile, he specializes in minimally invasive live donor surgery.