Welcome to the best forum ever for this bike!
Being a california model only makes one small difference - it's slightly 'cleaner'. It's got a can to collect unburnt fuel vapors. A lot of people just remove and trash them. Myself, I wouldn't mind it as it has no bearing on anything else, other than a tiny bit of added weight.
Holeshot is a great exhaust, but stage 1 is widely regarded a mostly useless around here. Best jet kit for performance comes from our resident guru - Sean Morley. See the ads for Morley's Muscle at the top of the page..