Thanks for the input guys, im glad I found out there might be heat issues before I actually started..
Unfortunatly I was trying to setup for personal use. If I had the money, I would be buying all the stuff i saw in "Ultimate Grow". Unfortunatly, I am on a budget, most of which was being spend on the HPS lamp. I looked at Ballasts seperate, but then the total cost of lamp goes from ~250$ complete to 400$+ for the ballast, relector, assembly, and lamp. There was a similar model (250w for about 10$ cheaper, figured it would be better to have 150w more light for 10$) that is the same dimmensions. Do you guys think that might be a better option for this grow room?
Unfortunatly, the house is built on a slab, no under to vent to. The bathroom is right next to the laundry room, so venting into the house might not be too much of a issue as long as I keep people away from my laundry (maybe dirty clothes could help hide the smell lol). Do you think it might be worth it to reverse the polarity on that fan to make it a Intake then passively vent into the house?
The price of the light is really hindering me on this build. The complete system locally is gonna run me 250$. Is there a way to rig up some of my 80mm or 120mm fans to the ballast to keep it cool and get the all-in-one unit?
Maybe someone has a better idea for the space?

Basic Shot of the Area.

FAN
My measurements (5.5ft high) stop at the bottom of the shower head, I have all that space above but did not factor it in due to having strait sides on my box. The width measurements do take into account the shower handles! If anyone has any ideas your help if greatly appreciated. Thanks.