Z71 roof rack backup lights

I was wondering if anyone had any info on where I can purchase and get info, on lights to be installed where the circles are on the back of my Z71 roof rack. I asked the dealer for info on them and he said they do not exist. I realize it is not a factory option, but have seen pics of them on the net. Any help would be appreciated! Thanks

I'm looking to do the same thing. Did you ever learn any info on it? Thanks.