Servo: The fastest that you can afford, speed of.1 of a sec or better and at least 7kg of torque.
ESC/MOTOR: Horses for courses really, TBH i use a HobbyKing Xcar 60A esc and Hobbyking Xcar 10.5T brushless setup in my drift car. Total cost about 60 bucks and its more than adequate for the task. Personally i do not see any need to spend big bucks on gear for drifting as long as what you are using is reliable. What you need is throttle feel and even power delivery, so use whatever you want really, as long as it feels good to you and is reliable.
That said, i would use a 10.5T / 3200KV motor and 60A esc, for a good balance of straight line speed and ease of breaking traction.