I called Firebird Central (same company as Camaro Central )and they said those rotors are not available.
As for the difference in price between the $120 $225 2-piece (I assume you are looking at HBC), the hub is supposed to be ductile iron and the rotor is gray iron and made in the USA whereby the $120 unit is gray iron for hub, rotor and is imported. I wonder now if the reproductions, imported or not, still have to meet US requirements from DOT, NHTSA or whomever.
Mike