You mention wanting a product that would be easy to write about. I am not sure what you mean by easy, but I assume you are looking for something on which there is a lot of information easily accessed, and easy to understand and communicate.
In this category, I would recommend pharmaceuticals. There are many restrictions on the importation of drugs, involving quality, effectiveness and safety. There are also issues of tariffs and licensing.
You could find plenty of material for a good discussion on these matters by researching the Internet availability of Canadian drugs for American patients.
I would suggest picking one highly popular drug such as the anti-cholesterol medication Lipitor, or one of the erectile dysfunction drugs. You should include in your discussion any difference in regulations for drugs that are merely sold across international boarders via mail order, versus drugs that are actually imported to the U.S. and then sold here.