Centerforce claims that if the clutch disc is worn out, the pressure plate likely is, too. Not a bad position for clutches used in high-performance cars.
I guess you can mix another disc with the CF pressure plate, but knowing how carefully CF matches their components, I'd be leery of doing so. You might be better off selling the CF clutch set and buying the correct one.
Or at least be sure you have a blowproof bell housing.
FWIW, Cobras rarely require anything beyond the most basic clutch - a Centerforce I is plenty adequate. These are very light, high-powered cars, not like 4000-pound muscle cars. You don't need a monster-grip clutch for clean hookups. Your left knee will appreciate it, too.