I know nitro seems cool and all, but for a 6 year old I would steer clear of them. You will only make the experience a bad one. Start him/her with electric and then when he/she is older they can try nitro if they are still interested. If it must be a nitro I recommend anything from Ofna, they come with most items you will need in the box and are pretty reliable. Ideally you should find a hobby shop in your area and shop there, that way you know you can get parts when it breaks something.