nice work,
be careful growing in them cups, the soil wont dry out very quick as their is no drain holes so try not to over water as it will just cause the roots to rot and will really affect growth, you would be better off getting a long pot that fits in the bottom of the grow space so it fits all the way along, you could even build something and build a rectangle pot a few inches high and line it with plastic so you can fill it with compost, have a few drain holes in the bottom, then that way you could plant them in the same pot and they would all have more room for roots to grow, you wont want to many plants in their you could even get away with 1 plant,
you might also be better going 12-12 from seed as these plants really do grow like weeds and within 4 weeks they will be bigger than the grow space.
so go easy on the watering while your using them cups, if i was growing like that i would build something that fitted the bottom of the space from front to back and side to side so you could have the whole of the bottom as compost, like a long rectangle type pot which you could build easy using plastic, you dont really need to build anything in fact you could just use a grow bag and take some of the compost out so the grow bag fits perfectly in the bottom of the grow space, that will give the plants plenty of root growth and would encourage them to grow length ways as the roots will have more room going the one way,
not sure what others think but i think that would be a good option,
also with the cfls if you have a look you will notice that they give off a lot more light off the sides of the bulbs, you dont get much light off the ends of the bulbs so your losing a lot of light, i know it might not be possible but if it is try and have the bulbs side on to the plants, you will also benefit from having the lights much closer to the plants, with cfls you can pretty much have them touching the plants before it starts to burn them, cfls need to be within 2 to 4 inches of the tops of the plants else they will just stretch and be lanky,
cfls keep plants short and bushy if the cfls are close enough, i grow using a 400watt hps but if i start plants under it they stretch like crazy, so is use cfls to start seedlings and clones as node spacing is very tight and plants dont stretch at all, but if the cfls are to far away from the plants then they will stretch, the best distance i find is 2inch from top of the plant,
if you hold the back of your hand agains the bulb then slowly more your hand away you will notice how quick the light drops off once you get past about 2 inches, so keeping the cfls close to the plants will really pay off,
also i think a good option would to be grow just 1 plant and use low stress training, if you had a grow bag fitted in the bottom of the case, you would need to take a lot of compost out as the bag would be to big but if you find a way to have the compost the same size as the case but a couple of inches deep then you could start the plant at one end of the case then keep tying it down so it grows along the bottom of the grow bag until it reaches the other end of the case, if you use low stress training the plant will then have many tops, when you tie the stem down and make it run along the ground the side branches then grow upwards and become the top of the plant, i think this would work very well in your case, if you let the plants grow without lst then you will have just 1 main cola and the lower side branches,
im not sure if you mentioned this before but im sure i read somewhere you was going to use lst, might be wrong as im subd to a lot of journals, but i think 1 plant using lst will give you the most yield, i think 2 plants would end up filling the case before it has chance to flower, the plants soon grow like crazy and easily an inch a day, so will need tying down and possible 12-12 from seed,