For the initial cross, it pretty much doesn't matter which parent is which. Kind of better to use a bantam turken if possible, so you won't have to battle overly large birds in later generations (unless you want some to be large/largish).
The comments about it taking several generations to get decent birds is quite right. The first generation crosses will all have "normal" feathers not silky. Then the first few generations of silky feathered birds usually tends to have "not that good fur".. especially over the wing area and the tails tend to be too narrow, a good silkie and showgirl tail is quite wide, very well cushioned and short with no "point" to the tip.
Also a challenge is to get good crest AND leg feathering on the same bird, it seems a common thing for a bird to have great crest but oh so little leg feathering and vice versa.
It helps immensely to use silkies from good show stock.. yes expensive but really helps in getting you good showgirls in far fewer generations than a hatchery stock or non-show quality stock.
You always need to keep and breed at least one naked necked bird, it is best to keep breeding to a silkie until you hit on the type you are happy with. Breeding back to a turken or to another showgirl not quite there yet in type can really set back the breeding by several generations. It does not matter which sex the naked neck bird is.. can be a showgirl rooster on a silkie hens or silkie rooster on showgirl hens.. both pairings will give at least half showgirl chicks. Just have to make sure one of the parents has a naked neck.. otherwise you will never naked neck chicks.
OEGBman- you got it right. Naked neck is a dominant trait, so the heterozygotes exhibit this trait.. silkie is an simple recessive trait.