OK guys here is a very good post on SB100 over at Club Cobra. Those guys outnumber us by a 100 to 1 in California and have had a lot of experience with SB 100. I would recommend going over there and using their search engine with "SB100" or "California registration". Its really the best source I have come across so far.
Don't get all wound up around the axel just follow the law. It works and I don't know of a single car that didn't get correctly registered in the end. Where you see Cobra substitute GT40 and use 1965 as the ordinals cars model year.
Scott - I will be happy to post a follow up to let you know how it went. I believe Howard is absolutely spot on when he says you just need to follow the letter of the law nothing more and nothing less.