The last 2 years we’ve gone we’ve used day tickets/APs to enter around 2:00. There is no wrist band distribution that you can get towards the entrance of the park. They’re handing those wrist bands as you enter from the “party ticket queue”. We’ve always had to get our wrist bands at either Adventureland, near Tortuga Tavern, or Tomorrowland, across from Monsters Inc. And the queue was very long when we lined up at 3:30. The Adventureland queue, for whatever reason, seems shorter.
I’d plan on meeting Jack and Sally layer during the party if it’s a must and you don’t want a long wait-time.