These are pretty sweet: 357 Magnum Bullet Gun Plugs. Sizes / gauges are limited to 2G, 0G, 00G, 1/2", 9/16", 5/8". These are sold in pairs starting at $13/pair. Double sided "O" rings to secure a nice fit in your stretched lobes. Made from 316L stainless steel. The plugs are shiny and fit comfortably.
If you're into bullet plugs you can also see the Spinning Gun Chamber Bullet Plugs released a few months back.