Here you go...  I'm not sure exactly which bits are of interest, so I wrote everything I could think of in the attached text file. It's just the setup that I used for the demo renders, and in no way intended as advice on what settings you should use for your renders of your scenes. I'd be happy to answer any questions about any of the settings, though.

To be honest, simple surfaces like this in a bright test setting are fairly easy to light well, as long as you gamma correct.

I think the main points are that I used gamma correction (Poser Pro), an HDRI background image on bagginsbill's EnvSphere, a matching HDRI light probe on the IBL light, an ISF light just above the two spheres, and a standard spotlight to the right of the camera.

The materials for the spheres were as posted earlier, except the left sphere has only the Reflect node and zero diffuse colour. The tiles are a shader I am still working on, to be a freebie if I ever finish it.

"If I were a shadow, I know I wouldn't like to be half of what I should be."
Mr Otsuka, the old black tomcat in Kafka on the Shore (Haruki Murakami)