Since you specifically asked about sushi, it bears mentioning that the most important part is the rice.
Here is a recipe. There is ample short grain available at the local Japanese markets, so you should definitely seek that out.
Since Hon-wasabi really is not available at least the kind you would use for sushi, I would seek out or make yourself Yuzu Kosho, it's the wasabi of western japan, and is better suited to So-Cal tastes anyways. Try lemon or lime zest, or a blend.
It occurred to me that many fishermen are able to catch market squid, and that it is one of my favorite nigirizushi toppings, but if you do catch them, your knifework needs to be on point.
I found a video which details Sabazushi in the Kyoto style, it's
here if you are interested.