HELP!!! non techy mother looking for advice on which xbox to get.....I am getting a lot of "storage" concerns from sales people trying to upsell. I have a 7 year old who wants to play minecraft online with the xbox. The concern is that I will spend hundreds on something that will not grow with him but the bottom line is, he wants to play minecraft and I want to use the kinect to dance (ok, I said it out loud) PLEASE HELP!!! Which console will be better and can I buy a cheap hard drive to store if needed?