A Barred Rock is more properly known as a Barred Plymouth Rock. Plymouth Rock is the breed, Barred is the colour variation.
You can get sexlinks by crossing almost any rooster over a barred hen. (Dominant white roosters, such as Leghorns, would hide the barring and so the chicks would be impossible to sex. But almost any other rooster over a (pure) Barred Rock hen should result in black chicks, with the males being barred.)
EDT: What I mean is that any other barred breed, such as the Dominique or a Bielfelder, would also produce sexlinked chicks. You just have to make sure that the parent breeds would produce dark-coloured offspring so that the white headspot stands out.