Size of bolt for extracting brake rotors

[1.8L]

I am getting ready to replace the rear brake on my 1995 GS-R. Does anyone know for sure what size bolts should be used for threading into the holes in the old rotor to help extract it? It looks to me like it is something like a M10x1.5.

Also wanted to double check that the brake rotors are the same for the LS,GS,GS-R. Some performance parts lists show a different part number for the GS-R, but other things that I look at only seem to be different for the later Type-R and the same for all the other models both VTEC and non.