Hey Stone...I had a similar setup a couple years ago in my closet...in order to maintain temps, I suggest you use a cooltube...I had one on my 250w hps, used along with a 6" In-Line Duct Booster Fan purchased from Home Depot and a cheap router speed controller from Harborfreight for exhaust...The only intake that closet had was the cracks between the folding doors and the temps were manageable...since you leave the doors open a little, i'm going to imagine even more better air circulation for your setup

Thanks Yike's... I'll probably find a stronger fan, I'll check that one out Home Depot,purchase a speed controller, then match the intake size(passive). If that dont do the job, I'll put my cool-tube back in and use it's own intake and exhaust... if I can fit it all in there...and I do want to be able to shut the door, if possible.

Those speed controllers only work with a brushless motor(fan). Makes sure you look for that when you go shopping.

Thanks Been...
Yike's... yeah, I found a 6in cheaper than the 4in I bought... thanks bro...