I have K3W, K4, KT and Fire, so nearly the whole set. But I am not too experienced in programming, just did a hell of translating based on SirAlex work. At least I got a lot of understanding where to find what. K4 not jailbroke yet, because it works well enough in German. Would do, if I could get useful things out of it, i.E. all the buttons in German. Theese I have translated "manually" as well.
You know, that Fire is easy to open for all languages? It is just installing a small apk which gives the way to the android localisation. To be found on xda-developers.