I cannot get proper instruction for the next months so I am training by myself. I am going into Kickboxing or comparable style. My upper body training is only jabs right now. I have seen three jab forms in instructionals. First without any shoulder or leg movement (boxing video), second with a twist of hips to add power (from a kickboxing video) and third with the back foot adding to the movement (this one from a Muay Thai video). Should I concentrate on the first one, without moving my base or torso, and punching only from arms or the styles that use kicks find it better for some reason to care more about the power of the move than the speed/defense? And should I train orthodox and south-paw jabs or stick only to orthodox? Also, what is the distance of the back hand to my jaw? Should I keep it touching it while punching or not change the normal defensive stance at all? Thanks.