Vertical yalll. Seriously Look

From my research it doesn't appear that you need more than 1kw, don't need to stack them and don't need a horizontal on top.

Tthat room was temporary though and they're on to a bigger room with much more light and space now. My camera's dead now though, that's why I showed that setup rather than the new room. (Which isn't impressive either anyway, I ran out of cash to do things up right and am making due with the bare minimums on everything.)

Having said that, look at other vertical growers of large plants such as Krusty (not me, I only wish I could do this) They just have 1kw bulbs up at the top and no lights down low and the results clearly speak for themselves.

Here is another example, just cause I happened to have that page open in another browser. (scroll down to the pics in this linked page)
http://www.thcfarmer.com/forums/f54/doubleds-again-28-light-hydro-garden-5271/index14.html

the whole thread is worth a read but here's one pic from the thread:

Doubleds grow in that link above is a good example of a big vertical.

that fool doubled has multiple rooms pulling like 2-2.5 per plant

I running a vert outdoor hydrogarden now. Its a tower system like the one above but made out of food grade uv resistant plastic. 20gallon res 20 plant spots, straight tap with chlorine and i have never seen such amazing results. example my cucumber seedlings were at their first set of leaves and now not even a month an a half later i have about 10 full grown cucumbers with multiple 4-6ft vines. But this is also outside. my ph stay stable and i change the rs every week or two, outside temp is about 95, water temp in mid to upper 80s, with no problems, i guess because its constanly circulating.

i have done vertical with no reflector and the bulb hanging down in the middle of the plants. had very nice buds.

Awesome illustration here. I feel like all one has to do is look at that photo to visualize the obvious benifits of vert