Where are you located? You can find King Fish steaks frozen at most ethnic/asian supermarkets. I've seen various Real Canadian Superstores carry them as well. In regards to Spiny Lobster, I assume you're looking for the fresh ones? I've seldom seen them at all, you might want to contact Diana's Seafood - I know they also carry King Fish.
2101 Lawrence Ave E, Toronto, ON M1R, CA