Not familiar with ideal protein.. this topic just grabbed my attention from the main page.
If you're looking to limit calories and fat, I'm sure you're familiar with the basics?
Nothing crunchy or tempura. These are deep fried.
Nothing "spicy" as this usually just = mayonnaise.
Sashimi is definitely your best bet. I love sashimi with a thin slice of cucumber on top.
When I order sushi, I stick to the basics, because I like to actually like to taste the fresh fish. Otherwise, it's just a mouth full of squishy flavors. my favorite basic rolls are Tuna/Avocado, Salmon/Cucumber, Yellowtail/Scallion, and White Tuna. A lot of places are now carrying brown rice in substitution for white. (for a price)
Miso soup is low calorie, and filling albeit high in sodium. Edamame is also awesome.
Dunno if this helped.