Jay,
I do not know the rotor adaptor to hub bolt circle. I used the Moser supplied adaptor but I did have to find a source for the rotor it's self. The rotor mount is 8x7" but I needed a 1.1" thick x13" dia rotor for the C6 calipers so I had to have a pair of custom rotors made 1.1" thick to fit the 8x7" mount. Interestingly, the custom rotors were cheaper than standard Wilwood rotors. As for the snout ID I never measured it but a Ford 31 spline axle will fit through it if that helps.
PS. If anyone needs a source for custom rotors I purchased them from Coleman Racing.
http://www.colemanracing.com/Default.aspx