we put sesame seeds on our sushi. And mayonnaise. And avocado. None of which are very low fat. But you could do without them.
Yo Sushi is a bit inferior (ingredients not fresh perhaps?), but their cookbook works very well:
www.amazon.co.uk/YO-Sushi-Japanese-Kimiko-Barber/dp/0007241283
Pretty easy to make really. You need sushi rice, rice vinegar, salt, sugar. I put a bit of dashi stock powder in the rice cooking water as well
Tuna sushi is raw tuna, sushi tuna is supposed to be flash-frozen to kill parasites. I think it's best to avoid supermarket tuna. The salmon in supermarket sushi is also raw, it's not smoked. You CAN use smoked salmon though. As for prawns, best get a kilo of frozen prawns from a Chinese supermarket, they aren't raw, but flash boiled.
If you want to make a couple of days worth at once, best to avoid avocado, as it goes soft quickly. Crab sticks are inherently not very nice, but make good sushi. You can also make egg (omelette) sushi quite easily.
You'll need a mat to make some types of sushi. Handrolls don't need a mat, and are good because they contain lots of rice - more filling. The mayonnaise you can make by mixing mayonnaise with wasabi and possibly ginger.