I contacted Henry at Supertec and he was kind enough to respond. He said the 993 crank is a 180 degree crank. No bob weights are used. He said most any shop that has a balance machine can do this. Here are the net takeaways for a 993 crankshaft balance:
1. Crankshaft gets balanced by itself without bob weights. I guess you could call this zero balanced.
2. The Flywheel, Pressure Plate and Pulley each get zero balanced individually.
3. The pistons including snap rings, rings and wrist pins optimally should be the same weight ( I read somewhere they all should be within .5 grams, this is what Costa Mesa R&D does). All six are weighed and the lightest one put aside. The remaining 5 have material removed from the wrist pin bosses or the inner skirt.
4. Both ends of the rods must be balanced separately. A special jig is used to weigh the small end and material is removed from the small end's outer-most surface. The lightest of the six is put aside and then the other 5 get material removed to within .5 grams of the lightest small end. To balance the big end all the rods are weighed (this time without the special jig) and the lightest put aside. The other 5 get material removed from the big end's outermost surface. This could be done with the bearings in or out because the weight difference of these is negligible, particularly if they are new. To see this being done look here:
http://www.youtube.com/watch?v=QLpiF0E0EJU