The top 328 cards in Modern from the large selection (26,579 cards) I have looked at can be considered their own set. Many of these cards, at least the ones issued from Mirrodin to Shards of Alara, should make it into Modern Masters. I have sleeved 100 of the cards I currently have that are in this list. If I include a playset of each card and two of each legendary, the cube comes out to 1,270 cards. I very much doubt I will even come close to completing this cube. I can at least show here the list of what should be in it.