PM sent. Project Threepio is just a pack of subtitles in various formats. I’ve sent you a link because they will be newer versions than what you got with most of the Despecialized Editions, and likely in a more easily usable format.
If the audio is off, it may be a transcoding problem. Try not to transcode unless you have to–there’s a technical HOWTO forum which is probably the best place to ask questions when you run into format-shifting issues. Selecting dubs and subtitles is a feature of the playback software, not the file. Just include all of the subtitles and dubs you need in the file, and the playback software should allow you to switch between them. Hope that helps.