Good-looking tends to refer to a person.
"She's a good-looking girl."
It can be used as a way to say "attractive" but is a bit more objective than that. You can call someone good-looking, without having to find them attractive yourself. But if you call someone attractive, you would generally mean that you find them attractive.
Nice looking (no hyphen) would more likely be used to refer to an object.
"She's wearing a nice looking dress."
"I've just bought a nice looking painting."
You may hear "good-looking" or even "attractive" being used to refer to an object, but it is usually an attempt to personalise the object. So for example, you may hear someone describing a car as good-looking, or even sexy, an old clock being described as handsome.
Gorgeous is stronger than both, but can refer to either:
"That girl is gorgeous."
"The garden was gorgeous."
"That sunset is gorgeous."
In the context you wrote, "What about" and "How about" mean exactly the same thing. I think they're fairly interchangable. I can't think of an example where one would be preferred over another, but maybe someone else will think of something.
Not a teacher.
Interested in Language