600 w hps grow area?

I have 3 plants currently in a veg room and I will be moving them into a flower room that is 6x2x8. i have a cooltube and i have an inline fan and carbon filter coming. the room also has a accessible window for intake and exhaust as well has having an air conditioning vent in it.

My original plan for flower room fell through and this is what im stuck with.

Do you think temperatures will be sustainable?

I also worry that that 2 foot width is too skinny. I run the lamp parallel with the walls hoping to reduce direct light on the walls.

Any ideas and comments are welcome. Thanks in advance. if i can find a camera i may snap a picture

im in the midst of building it obviously. but im really starting to get some doubt so i kinda was looking for feedback

sorry for crappy pics, webcam didnt have enough cord

and the material is:

http://www.acehardware.com/product/index.jsp?productId=1296203&cagpspn=pla

i searched all day and it was the best i could find around here.

the 600 was a steal so im bound to using it.

bump please i dont wanna burn my house down

I ran the light for a good hour with no venting on hood, ran a fan in grow area. the light powered up and was that florescent color then switched to that hps orange color. after too long the light switched to florescent color again. it is a digital ballast,
is there anyway that the bulb got too hot and it lessened the intensity?