Hello! Our daughter's 7th birthday is coming up in July and she would like a video game system. We also have a son who will turn 6 in December so this will be a joint birthday gift since he wants one, too. What game system is considered the best for children this age that will grow with them? My husband and I know nothing about video games - he still plays his old Intellivision. I have looked at the Nintendo Wii U but can you only use 1 gamepad or can you buy a 2nd one? I can see lots of fighting in our future if you can only use 1. I would very much appreciate advice from the experts on what to buy and any additional accessories I would need so they can both play. Thank you!