The Labs Pageviews tool has a UI language selector at the top. It is a dropdown with dozens of items, and it's hard to find a language the right language there.
Precisely for cases like this the Universal Language Selector was made. It can be used without MediaWiki, as a standalone jquery component. See https://github.com/wikimedia/jquery.uls . You apply is at a plugin function .uls() to the element to which you want to attach it, and you'll need to provide the list of languages (which you already have) and a function to do on selection (reload the page with a new language). The sorting by continent and script family is done automatically.