pretty much! to add on, sugar is also sometimes sprinkled directly onto the bread. american sliced cheese will suffice since it's cheap, accessible, and easy to work with. any type of meat will do, such as spam, ham, or bacon. they're all slightly salty (maybe even sweet depending on the flavouring), and also easy to work with.

for the egg mix, there's a lot of directions you can go with it, adding all different kinds of sweet and/or crunchy veggies. i personally prefer a crunchy sandwich, but lots of people make it with just egg and maybe cheese and corn.

if i hadn't stressed it enough, the sandwich is meant to be very sweet with a little salty flavour.