The last one I vegged about eight weeks, but it took longer because the topping halted growth for a week. The first time I grew Sativa I used 1-gallon size pots, but I had more germinate than I expected so I had one that was left in the 1/2 gallon starter pot and it grew to be the same size as the others, so this last grow I left them in the starter containers (cut off milk jugs) and so far it looks like I'm going to have at least as large a yield. Also this time, I used a 50/50 mix of 2700k and 6500k cfl's for the whole grow (last time I changed from 6500k's to 2700k's when I went to 12/12) and my plants look better this time. My grow box is really short so I've got to do anything I can to keep my plants from hitting the lights, and doing it this way I've been able to keep my plants from getting more than 12 inches above the rim of the pots. If they were stretched out they'd probably be close to 3 feet, but that length is kept horizontal rather than vertical. Oh, and I've found for LST twine and clothespins work really well. I tie the the branch loosely with a surgeons knot (an overhand knot with an extra go round) and then pull it down towards the edge of the pot and clip it (the string) in place with the clothespin. This way you can adjust the strings without undoing anything.
Good luck - Dr.Nick