Both should be fine m8 around 19turns if where you wanna be for a good torquey drift motor and like you said you can change out the tyres and put some speed down too,looks like youve done your homework on setting up a drift package already
Only thing i could add would be looking at the newer designed E version of the TT kit as the front end steering is designed better.
Also the motors with 19x2 etc will add more torque for slower technique drifting i used a method 19x2 with good results