Hi Trond,
The Castle 5.5mm High Current Bullet Connectors are a good choice, they will take Upto 150A of current, another good choice for motor connectors are the 6mm connectors from scorpion or the 6mm bullet connectors from SupraX. Both these bullets have longer bullets and give a greater surface area, the SupraX connectors have a click 'n' Lock design which helps to keep the bullet secure and in place.
In regards to the method of installing the bullets on the motor and ESC, the industry standard is to install the male bullet on the motor and the female part of the bullet on the ESC motor connection wires.
Hope this helps, any questions give us a shout.
Cheers,
Ross