The cork is ok, that's what was originally there but it well in a relativly short time become saturated with oil and you will see dust collecting around the edges of the cover where it's damp with motor oil.
If I had the option I would go with the composite gasket.
Of course Permatex #2 is avalable at Every automotive store in the world and every farm supply and most big box stores that have an automotive section, and that's a bunch of choices fo sho!
DG