Diaper help?! FTM please help

Okie so little guy is due Oct 11th but I wanna make sure I have everything ready as might come in Sept...I am thinking of buying the Pamper Swaddlers newborn diapers that have 128 diapers and also buying the same but in size 1 that has 216 diapers. I was wondering if I would need to buy the newborn and if I do would I be using 128 diapers for newborn? Or should I buy two boxes of size 1 (216x2=432?) or is that number still too many diapers for size 1? I'm confused..any help would be greatly appreciated