Sounds great to me, Andrea! BD50 would be better especially for the length of the film and maximizing bitrate. DTS-ES 6.1 track would be a stellar idea too, since I do quite agree with bigrob.
I'd have it as Disc Three with the 2-Disc Sapphire Series Blu-ray release (Remastered film disc here.)
EDIT: How about having a hidden audio track (accessed via remote or summat), one in Japanese?