There are so many fonts that I’ve never heard of in Typography. How about having the font names in the drop down box spelled out in the way they would actually look on a page?
I’ve thought of doing that, but I think it would take up a lot of resources in the Customizer and might slow down performance considerably.
All of those fonts are pulled from http://google.com/fonts – so it’s best to browse there until you find the font you want, and then find it in the list.