As far as we know, Jason's new venture Harding Performance is the only company making billet-aluminum valve covers for the C8 Corvette. They'll also work on C7 Corvettes and late-model Camaros.
Harding Performance billet aluminum valve covers for Gen 5 LT engines are CNC machined from 6061-T6 billet aluminum for an extremely light weight and attractive design. They can be purchased in raw aluminum if you are going to be powdercoating yourself, or you can choose from a wide array of colors which also provide a protective finish. Even if you want the raw billet look, they recommend going with the clear powdercoat. Titanium fasteners are included and an be driven by either 10mm socket or 5mm allen, allowing for tool versatility for hard to reach areas.
Harding Performance has a full line of C7/C8/Camaro mods you should check out. See all of their great products at www.hardingperformance.com