When to flower (pics)

This is my first time growing on my own. Here's the set up: 4 white widow clones, picked them up two weeks ago from a club in sacramento(2 weeks old at the time). They are in 5 gallon square containers with organic soil from coconut. They were under 24 hr light from T5 cfls 2 2' 24 w bulbs for the first three days at my house, then I introduced a 400 watt hps. The room is 62 cubic feet, I have 2 oscilating fan and one inline fan changing the air 2.5 times per minute. Temp has stayed between 70-80 degrees f, humidity 35-55%. The room is lined with mylar film.
The plants are all growing well. I had some issues with watering, but got the hang of it eventually. The tallest is about 9 inches, the others close behind (some are undergoing LST). I was planning on growing them a foot before flowering
Will this be enough growth in the veg state to support a bountiful harvest? When I switch to flowering, how much will the plants grow? What about root growth? the soil is a foot deep, will they need a transplant before flowering? thanks for any help.

are you using any nutes?

you should wait till they are at least 4 feet before you flower (12/12)

^Lol, you can flower a one foot if you wanted.

I have encountered a lot of research and talked to a few people who are adament that you don't need to veg long indoor, especially with clones. The figure I encounter most is that the plants will double-triple in size during flowering. This is where my concerns come from. My room provides five feet between the light and the floor. I figure 1 foot for the container, a foot for the plant, a foot space from the light, which leaves two feet for growth.
I have read posts on this site from people who swear by low veg time with clones. I only have one 400 watt hps and two 24 watt cfls, so I don't see that penetrating one four foot tall plant, let alone four four foot tall plants. If I was to let them get four feet tall, I cant imagine their size after a month of flowereing.
I am using the nutes that came in my soil for now, 6-6-5 + 8% Ca. Unless anyone can offer me a good reason not to flower, I going to tomorrow(the biggest is almost 14" tall).
Will I need to transplant? All plants are almost a foot tall. They are in a 4.75 gallon square containers that are a foot deep.