I agree with mkrish- you're overrating ailerons. Get a Tiger Moth or a Slow Stick. Either can handle the space, are great fliers, and will be nice and slow for the kids to learn on.

Keep in mind that they're only 8 & 11 and they're ones learning to fly. After they master one of these, then you can get them one like Dad's. (Don't be surprised to discover these are a lot of fun yourself...)