RetroUSA sells them
http://www.retrousa.net/products/camaro-products. for $149. I've had them on since summer '10 - note that the black will chip off from kicked-up stones over time even with splash guards on (just like the original '69 gill louvers do). I got 1/2 inch dark charcoal metallic pinstripe tape to fix the passenger side. The chrome has held up well - they attach with provided 3M tape.