I would recommend one of the generic Mad Catz or other off brand controllers for a younger kid. They can take a little more abuse, the buttons are a little bigger, and if they do break, you won't have spent as much money.
The standard two thumb-sticks which come standard as part of Xbox 360 controllers are more than enough--a joystick is just expensive, and too complicated for a four year old.
If the child is decently careful, any controller would be ok to use. The controllers are pretty durable so there isn't a need to worry about it breaking easy.
