A 4x2x6 is going to be tight buddy. It will work but your headroom is going to hurt you some and the shoulder room for the ladies to stretch out is going to suffer. The side to side room isn't a killer because they just won't stretch out well to developers those branches. It will hurt your yield some but, hey, it's your first grow. It is all about learning right now. The headroom though, that is of concern because they won't quit growing vertically when you run out of room. I am not too sure what the average height for that specific strain is but you may want to start reading up on LST or low stress training. That may need to be implemented to keep those ladies short. You don't want to run out of space and have to chop the tops to keep them from hitting the lamp.
Your rh, if you can fit it inside the tent for the first couple of weeks that would be better. Heat isn't going to be much of an issue until they start getting big. By then you won't need the humidifier. Only the first couple of weeks, until the roots get developed.
Your rh, if you can fit it inside the tent for the first couple of weeks that would be better. Heat isn't going to be much of an issue until they start getting big. By then you won't need the humidifier. Only the first couple of weeks, until the roots get developed.