95 gets you to the "966" (964cc but 966 sounds better)
Stock: 904
924 (idiots kit or perhaps damaged cylinder and owner wanted to fix it but not make his money go very far)
944 (common)
964 (less common, more heat)
984 (requires case modification. the 'balls to the wall' mod)
methinks if you went to the 964, you'd want to investigate cooling options. Perhaps a higher capacity cooler (motowheels lists them, none in stock, but perhaps its a special order - can't be too many people regularly ordering these); alternatively an NCR oil cooler like DesmoWorks carries; or do what the old school guys had done, which is to use two of the horizontal cam inspection covers with oil cooler mounts and rig up two oil coolers to get the job done.
Example of one of my favorite motors, an older 900 build with ? ? ? displacement, MBP heads and lots of other cool stuff: