I’m going to buy one for my son and I wonder what else we need, E. g. chargers, bags, etc. I was on eBay and there is this 12 piece accessory kit, etc. Are these really necessary or should I just buy the device, and a few games to go with him? We live outside the U.S., now I’ve got everything at once. We travel a lot and I need enough battery life for us to get through the flights, airport transfers, etc. (4-6 hours or more would be great).