What would be most useful for the reader? Certainly not option 1 and 5. Option 4 may be nice, but I already got stuck at the search page and there was no way to get back to the original language (my mobile opens a new tab, and there is no back-button since the search page is the first page in this tab). Otherwise we don't know what other language the user may prefer, he could be satisfied with an English article as well. I prefer a language choice which also includes the option to search the French Wikipedia. If there is no good result you could go back one step to the language choice and change yours.
Btw: Are you using the Interwikilinks, or are you looking up if there is a similar named article on the other Wikipedia? Interwikilinks are often not used if there is only a redirect to a paragraph in another article.