Questions for Cali owners

I'm potentially going to be moving to SoCal for a job and have a couple questions for you Cali Miata owners.

I know Cali has pretty strict smog regulations and because of that I've read that there is a Cali spec NB (I drive a 99). My car is bone stock powertrain wise so I was wondering how feasible it is for it to pass with the non-Cali exhaust. I've also read on the Cali DMV site about registering cars not purchased in the state and am curious if that is a one time thing where I'd be exempt from the smog test or if I'd have to still pass smog every year.

Also since I do autocross monthly would a stock NB2 header still pass smog or would I be stuck with the NB1 boat anchor?