Putting 3 movies on one DVD+R DL

I got ahold of some Dual Layer discs, and I want to put the Star Wars Trilogy onto one Dual Layer disc.

I've used DVD Decryptor to rip the files onto my hard drive, then TMPGE DVD Author to import the main video file, but it won't recognize the AC3 audio.

So I used DVD Audio Extractor to rip out the audio to a wav file, but when I try to put them together, the audio is at a different length than the video so it won't sync up.

Does anyone have a tutorial (or have done this) and know how to do it? I would like to just create 3 separate video files (MPEG or AVI doesn't matter, as long as their DVD-compliant) so I can author using Adobe Encore (so I can add personalized menus.)

Thanks.