Want to start with that yes, turken(Naked Neck, some get bothered if "turken" is used.. so use NN if talking to show people, just in case) standard does call for single comb. And yellow legs. Yellow legs is simply yellow skin combined with gene (Id) for "no pigmentation in the skin". However, barring also has the side effect of repressing pigmentation in the legs so a barred can have either all clear or mostly clear legs without Id being present.
Turkens with yellow legs are not very common. Most of hatchery stock and also backyard stock have either green, blue or dark legs. (btw green legs is yellow skin without Id, blue legs is white skin without Id). I would not be very surprised if your new blues come with dark color legs.. BUT if they have yellow legs, they are very precious stock! (and talk to me privately if they do have yellow legs, please. Would like stock matching standard in my flock too..)
For breeding fun, you can do anything you want with them of course. Not worrying about the right leg color will make your color projects a lot easier, especially if you didn't get any yellow leg birds. You can make red/buff turkens, easily, probably much easier than barred turkens.. just cross your blue barred boy with any red or buff turken hen.. then keep a son from this cross and breed him with a red or buff turken hen and you will get red or buff barred turkens. Pretty straightforward. However, be aware that barring shows best on black or more darkly pigmented feather so buff and red barreds likely won't have as clear and crisp barring but they are still very beautiful.
For show standards, you will have to try for yellow leg stock, this will be harder. Black turkens with yellow legs is on a different base than black in other chickens so you cannot cross with say a barred rock to try for black turkens with yellow legs.. they will pretty much all have dark colored legs. This is because the black base of barred rocks is completely different from a yellow legged black.. the legs are yellow on barred rocks only because it is a side effect of the barring gene.. magically take away the barring, their legs will suddenly turn solid black too.
For sex linked mating, it has to be the hen with the sex linked gene and the rooster not having it. For example, black rooster x barred hen, will be sex linked(all sons barred all daughters black). But if you reverse it to barred rooster and black hen, ALL of the offspring will be barred, in both sexes.
