Mid size PC Veg question

I need to start about 10 plants inside and will be putting them in a mid size PC case with 2 CFLs. The plants will be put in party cups...My question is, how long do you think they can grow in there before they get to big. I want to plan this out so i can move them outside at the right time.

Plants are x-line White widow x Big bud and GH Lemon haze x skunk

i'd guess 3 to 4 weeks from germination

these cups are going to be side by side. 8 is the max i can fit in the case but yeah i was thinking after germination, probably 2-3 weeks max.

2 cfls wont give 8 plants enough light.