Grow box size for harvest?

How big should i build my grow box if i am planning on harvesting 2 plants which are about 12 inches tall before i force budding. Also, i just bought a 125 watt cfl bulb, is this sufficient for veg? And would several of these work ok for budding?

Well. At the end of flowering, they should be about 24 inches tall. So a good few feet. For two plants, a 125 watt cfl should be fine. Get some more so you can get them around the plant, and get her growing outwards a bit. Prune her a little, you will get a pretty little harvest bud.

I have a reflector focusing the light, but yeah i am ok with a mediocre harvest because its at a friends and i dont want it to smell like a grateful dead concert when theyre budding.