I want to buy and have seen many covers for vortec heads.I have not seen any with PCV and breather holes that are polished  aluminum,only those that are stamped steel seem to have the holes.What application would use no PCV or breather?

You have to drill holes for the breather and PCV. That way you can locate the holes where you want them.

Stamped valve covers generally come already drilled since they need a rolled edge to keep from cutting through a grommet or simply bending and creating points for leaks..