if you want the "cadillac of Welsummers" you would be hard pressed to find them from original stock of Lowell Barber, Bjorn Netland, and other good folks that has them. Do your research on the lines and if the breeder refuses, it could be either they dont want to tell or they got hatchery Welsummers intead.
Whitmore Farms, Tailfeathers (Royce) and Amazondoc and Mother Mastiff are the ones I know of right off bat.