I think you should get AP version Magic Bands (which are just MBs with a little AP slider) if you have APs linked to your upcoming on site stay. Then you would get the box with the AP discount cards in it. You can always stop by guest relations in the parks to get the actual AP cards.
I'm not entirely sure of this because we upgraded during our trip and after we got home, we got a notice to customize new bands and they were just mailed to us after our trip.
Maybe someone else can confirm how it worked for them when they bought their APs in advance.