Yes, you are correct. Showgirls are indeed a breed of chicken that has unique naked necks and feather tufts, resulting in an unusual and unique appearance. They are a cross between a Silkie chicken and another breed with naked necks, such as a Naked Neck chicken or a Turkener chicken.
The breed of Chinese chicken with feathers that do not have barbs, mentioned by you, might be the "Naked Neck" chicken, also known as the "Turken chicken" or "Transylvanian Naked Neck". They have a striking appearance with featherless necks and a fleshy red head, which make them stand out from other chicken breeds.
Regarding the origin of the Silkie chicken, it is uncertain. However, it is believed to have originated in China possibly as early as 200 B.C. Silkies were initially breed for their white meat and were later introduced to the Western world in the 18th century. The breed became quite popular in Europe and later in the United States owing to their unique appearance, good temperament, and ability to sit on and hatch eggs of other poultry breeds.