Btw, I haven't undub the dialogs yet cause of the lipsync problems reported, but probly it will be like the textures and simply have to rename the original files (i guess in snd.cpk) and bring over the files from the jpn game, I may try it later.
The jp files are apparently already in snd.cpk, we might just have to rename the folder. I did this yesterday, but I haven't done another story mission since then.