the internodes you would take as clones seem a bit small, maybe try some LST to get them to stretch out a bit before you take them.
I have to dissagree with Stumps, even if you dont know the sex theres no harm in grabbing a clone or 2 before you put it in flower. if it turns out to be a male then just dump the clones, if its a female you should have a couple rooted clones before long and dont have to worry about when you flower the mother.
for cloning i have tried several methods and so far rockwool and cloning solution in a propogator seems to be working well, just my 2¢