Diggin on that hindukush photo.
My next grow I have been planning for.
I got a econo 400w hps lightsetup like you mentioned.

As far as heat is concerned I have read a lot of people saying 65-70 degrees? I am questioning this as I am new.

So I spent too much 100. and got a cool-tube dont know brand. Im going to vent it out my dryer vent with a Y ( still need to find ). Possibly this would help your grow rate? That way you can bring light closer to plants.

(Cool tube simple corningware or pyrex type tube that light fits into and you attach hose to either side of for fresh air intake as well as heat exhaust. It seemed to me that the smell would get magified with heat so pulling heat out of the enclosed space would help on smell also. ( this is just a guess )

I was also hoping that the fan nothing loud or radical could be helpful in pulling oxygen into the grow area in my case a cabinet. Possibly this would be of benifit for you.

jmho its all guesswork to me still. The proof is in your "holy grail" photo at the end of the story. ;>

Peace.

um P.S. need a roommate? hehehe
j/k on the roomie thing.
Went to amsterdam on our honeymoon it was very cool.

brotherbud