Hi, Kim!
Thank you for sending in your great question to the Disney Parks Moms Panel. So you'll be returning to Walt Disney World next month for your
fifth visit? That's awesome! I'm happy to tell you that both HDMI and A/V inputs are available in the rooms at
Disney's Pop Century Resort. I have not seen pay-as-you-go cell phones for sale in the merchandise shops in the parks or at the resorts, but you can certainly have one delivered to your resort.
Here is the mailing address for Pop Century:
Disney's Pop Century Resort
1050 Century Drive
Lake Buena Vista, FL 32830-8433
Tel. (407) 938-4000
Be sure to include your name and reservation confirmation number on the address label. As a complimentary service to resort guests, Pop Century will hold your package for you until your arrival. You should time delivery of your package not more than 10 days prior to your arrival.
I hope this helps, Kim! Please let me know if I can answer any other planning questions for you prior to your visit.