Need advice BL Savage

[tom255]

I have a Savage X all is stock, so i planning to make BL conversion. I have couple questions:
So i planning to use Feigao XL motor and BK9920 ESC.
Thinking about 12-14 setup is it OK?
Batteries GP3300 for start. How long aprox. RunTime i will get?
I think to leave stock 2 speed gearbox and mech. brakes for that.
I want to know good combination for motor? (6XL, 7XL, 8XL)
Which Spur and pinion combination i should to get to reach top speed 40-45mph?

Want to get nice compromice between RunTime/Torque/Speed. Just simple to smoke Nitro brothers :028: