I am buying an axial artr but I am not sure what electronics to get. I am looking to spend up to $140.00 total on electronics. I do have a tower hobbies model 420 ac/dc charger(is this good enough) that is about 6 years old. I dont know anything about the electronics so I would appreciate suggestions. It will be used for backyard fun only(not to compete). Also, what are the run times for different size batteries. Thanks