Chances are the brushed versions have the silver can motor, I cant imagine whatever brushless setup tamiya is putting in would be complete trash. But I'd hold out for a website that I can read just to be safe.

I agree that your 6 year old would be able to handle a stock hornet or grasshopper. And you can speed those up with brushless later if desired.

Another thing to think of is batteries. Those appear to come with nimh batteries which is old tech at this point. If you buy the 'not ready to roll' package and get your own lipo batteries and charger you'll be better off.