It takes many generations to get a quality showgirl. However, as Dipsy said, only two to get a silkie feathered naked neck.
F1s wil all carry H/h (one copy non-silkie, one copy silkie); depending on the particular naked neck, they may all be naked necks or only about half. Naked neck always shows.
Cross one of the naked neck F1s to a silkie and half should have silkie feathering; the others will all carry one copy (genetically they are the same as the F1 generation for silkie feathering, but you should see better crests and foot feathering)