Purchasing flash frozen fish

by Doug
(Morgan Hill, CA USA)

My wife and I love sushi and since I love to cook, my next challenge is mastering sushi at home.

We are lucky to have a large market (Mitsuwa Marketplace) in San Jose, CA. I went there on a scouting mission to see what assortments of fish were available and they have a nice selection.

We prefer nigiri/chirashi versus rolls because of the variety they offer. We'd have to purchase many pounds of different kinds of fish to achieve this for one meal. Given the shelf life is only 3-5 days in the fridge we'd need to eat sushi for many nights in a row or waste it unless there is a better way to purchase and store fish from the market.

Question:
I'm assuming most fish is flash frozen, then shipped to individual markets. Do they then defrost, butcher and portion out small quantities for packaging for their customers (me)? The reason I ask is at this market I saw some fish that was still quite frozen. Has this fish be refrozen or is it still in it's original flash frozen state?

What I'm getting at is ideally I'd be able to purchase smaller portions of a variety of fish that is still flash frozen (never been thawed out or refrozen). That way, I can keep it in my freezer and just cut off small portions based on my needs for any given meal.

Apologizes for the long winded question.

Thanks in advance,
Doug