If I'm looking for Porsche part numbers I just go to the Porsche online PET rather than via a 3rd party.
http://www.porsche.com/uk/accessorie...artscatalogue/
I had an issue accessing the 996GT3 catalogue but the 996 catalogue list two possible options for the ring gear bolts (with LSD).
999 217 152 01 or 996 332 276 00 depending on which diff (can't quite read the full number in your photos).
The GT2 catalogue lists the 999 217 152 01 bolt for use with the 996 332 083 9B (40/65% GKN) diff. The bolts are M12 x 1.5 x 22,5
Hope that helps.