Looking to buy a small car that's super-quick

[ReV:-O]

A few people have told me to go for either a Rustler or a Bandit, but I have a few questions regarding them. They also told me that since the battery tray is so small, I would not be able to run 4s. Also, they said the Traxxas esc wouldn't be able to handle it unless i got an external BEC, and even then it would likely end up in flames.

If I got a Rustler/Bandit, I wouldn't want the 3500kv motor, I'd wanna get something with a higher kv, maybe around 4800kv if I'm only gonna be running 3s.

Traxxas claim it to be waterproof, but how can this be when the motor and lipo are exposed? Are brushless motors waterproof? I know lipo's arn't!