which light setup is better? pic

Looking for some advice or tips from people who know this stuff, these are 600w cooltubes I'm trying to decide how to setup for cooling/light efficiency reasons...I'm using a 340cfm fan in a 800 cubic foot room...

so what do you think will be better? pic attached...

2nd one is better if you have adequate ventilation

and it seems that you would with what you said you have

In my opinon the first one.

get a cheap light meter and see how each method does
then you decide