It really depends what surface you will be racing or drifting. In my experience stay away from the automatic esc’s these can be difficult to setup as they sometime get your settings wrong, and when this happens all you can do is turn it off and reset it.

As far as the motors go I think a 15T will be too much power for drifting, I normally use a 23T sport-tuned motor. But more power is always more fun, a lot of the guys I drift with have started using brushless motors, although this IMO is total over-kill

These is no “best” motor or ESC personally I only use ESC’s that don’t have reverse, or at least ones where it can be disabled. Drifting requires a lot less motor power, the most important thing is that you setup the car and the chassic modifications.

For racing the gearing is the most important part, I’ve seen a standard “silver can” motor outpace a 17T motor, although I’ve personally never been able to get them to perform like that.

For details on modifying a RC drifting checkout my RC drifting modification guide