This is just what I have been looking for!
I have wanted to build something like this but was leery of trying it because the other plans I have seen were much more complicated than your idea.
I do have one question..... How are your fans wired into the adapter? The adapters I have seen have the little plugs at the ends. Do the fans have the same type of plugs? I am thinking about using an adjustable converter so I can control the speed of the fans. Can't wait to get building!!