Hope the deluxe box set will be available to pre order from amazon.de, ADTOE wasn't, if i remember well it was available from roadrunnerUK. If the release date is the 9/20 here in germany i wouldn't like to wait till 9/24, and shipping from the US could even take longer.
The band seems to be open to fans wishes, i don't think the original plan was to release anything else from Mangini's audition. And if by high quality FLAC they mean the HD tracks, then the box set is almost perfect. Only critique point is that they only release the stems for Behind the Veil.