Puff420,
Thanks for the ideas and the pics... As to ventilation, here's what I had thought out:::

There are TWO independent air systems in the cabinet; 1- Plant's air, 2- Lights reflector's air.
Both systems take air from the outside (right side) and push them through, again, to the outside (left side of the box).
1- Plant's air:
The air comes from the right side wall of the cabinet, in through the lower level of the 'mother room'.

....

Ok, this shit is getting mightly complicated.... what you say I draw the fans and stuff in AutoCAD and then I re-upload new pics... I think that'll be better than writing all this stuff down.

Thanks for the input and ideas! Please keep them coming....

-turtle420

PS: The grow room is going to be 19" x 29" aproximately... what size of lights? How many plants? I've asked this before, but Now I think that the idea is more concrete.

I was thinking of buying a dual-ballast 1000W system... and using the 600W HPS bulb only... in the future, when space permits, all I've got to do is plug-in the other 400W MH bulb...
As to how many plants... ??? I was thinking of making three PVC rows for the hydro NFT setup... and placing three plants per row... total of 9 plants... 9plants, 19"x29"... what do you think?

Thanks!