Brushless motor on TT-01? Gear ratio needed is hard to achieve....If you want to confirm the effectiveness of my suggestion, you can take your motor to model shop for comm cutting before you go further. About batteries, well, you need good batteries anyway if you want to go fast, no matter what system you use.
In my opinion, a comm lathe worths any penny if you plan to play on in 23T class. Brushless system is another story. I think you need another car 'cause, for example, with a 3.5R system it needs a gear ratio around 12:1, which is almost impossible with TT-01.
Gear ratio needed is hard to achieve....If you want to confirm the effectiveness of my suggestion, you can take your motor to model shop for comm cutting before you go further. About batteries, well, you need good batteries anyway if you want to go fast, no matter what system you use.