As far as I know, the first HD version was the one broadcasted on the German HDTV (7MAXX IIRC), in 16/9; no 4/3 HD, nor 480p. Again, AFAIK.
The only way to get the best quality is to find out if the laserdiscs are better than DVDs (highly unlikely), or combine both PAL and NTSC DVDs (and add some cleaning filter) to obtain a better upscaled version than each single PAL or NTSC upscale.