Will a 400 mh light be enough for....

Okay so right now I have a seedling/clone box with roughly 240watts of flourescent light that I start the babies in. Im shooting for 6 plants in soil and I have a 1000 watt hps for the flowering room. Now im trying to decide what kind of mh light I should get for six veging indicia plants. The seedling/clone box will be good for about three weeks, than I will move them to the veg room. Than after about one and a half months of vegging I will cut clones from the plants (and put them in the seedling/clone box) before moving them to the flowering room. So my question is what watt mh lamp should I get a 400, 600, or 1000? Im guessing the 1000 is to much because the veg room will be relatively small so Im deciding a 600 or 400 watt. Heat and space is definitely a factor so im shooting for the lower wattage but will 400 watts be enough for six vegging plants? Im not sure of the dimentions of the veg room yet but it will not be over 7x7x7. The operation will be entirely soil, indoors, temp right now is average 65 during the night and 80 during the day. Ventilation will be limited but it shouldn't be a problem.

Any suggestions of a proper wattage for the ml lamp?confused:

I'm currently vegin 70 under a 400 watt metal halide. I will have to give them a little more space soon, but its going good so far.

I would think a 400W would do fine. I'm about to veg 18 plants under one.

Can you guys post pics of the plants you're growing under the 400 watt MH? (Those that can grow 10+ plants under one... How big do you guys grow the plants?). If I'm not mistaken, this light should produce less than 40,000 lumen. Sun is 10,000 lumen PER SQUARE FOOT (How many plants per square foot do you guys plant?). I guess my question is, would it help to add a few CFLs or strips around the plants to add a few extra lumen or would it be overkill and aversive if it interrupts airflow and increases heat?