Looking for a 7" Android tablet that can play movies for 8 hours. It must have a microSDHC slot to hold alot of movies. Access to Google Play is also important. The nook tablet 8GB looks like it would work for $179. Is there anything cheaper that is similar to it? One concern I have is charging/powering the tablet in the car. Does it have to be OEM or will a generic usb car charger work?