400 or 600W for 36x36x72 tent

Getting this tent

http://www.amazon.com/gp/product/B00H9N29SC?keywords=grow tent&qid=1447113594&ref_=sr_1_8&sr=8-8

wondering if i should get this 400w
http://www.amazon.com/Apollo-Horticulture-GLK400LS24-Digital-Dimmable/dp/B005ECY4UQ/ref=sr_1_8?ie=UTF8&qid=1447112892&sr=8-8&keywords=400w+hps

or the 600w version of this apollo .

I will also buy the 240 cfm inline fan & another small clip fan to move air around.
unless this wont be enough ?

let me know thanks

600

yeah...I vote 600 too.

600 and 460cfm fan.