i feel it would be a little stronger cutting if it were topped a little lower. then when it does take root i will be that much bigger.
with the plant i would leave 5 -6 sets of nodes. then continue to veg until ALL the nodes are at least 12". if you flower it now after topping you are looking at about a 1/4 ounce of smoke. i don't know how much room you have to play with but that plant, in my opinion is to small to produce a worthwhile yield. not to say it won't give good bud, i would just let it veg more. ramblerambleramble..........