I'm having the same problem with my grow at the moment. Into the second week of flower and I have 5 plants of varying height. I need to get down to just 2 or three healthy plants for the space I've got then I'm going to create a makeshift SCROG to manage the height and make the most of my space. You Could top yours but it may be too stressful for the plant now and you'll reduce yield. Also, taking clones at this stage is still possible but not advisable. That should really be done in the veg stage. Have a read up on SCROG setups and see if you can gently train your plants to maintain an consistent canopy. That's what I'm going to do. Check out my thread http://boards.cannabis.com/indoor-gr...-10-years.html so you can see my setup. It's getting a little crowded in there!

Good luck!