Here's the canned version, PF:
MARUKAI e-STORE - INARIZUSHI NO MOTO NET WT. 10 OZ.
If you ask your local storekeeper to look for some on his next run, be aware that fried tofu is packaged in two forms: blocks or sheets. You want the latter kind to make them yourself into inari pockets, though the blocks are good in stir-fries and braises, too.
As for other ingredient ideas in an inarisushi, anything you favorably associate with sushi rice will work well, and beyond that, I'd try to think of ingredients as bits of texture. Cousin to the inarizushi is rolled futomaki ("fat roll"), and some ingredients common to it are: lotus root, re-hydrated kanpyo gourd, spinach, and pickled daikon radish.