i would suggest getting or building a small cabinet over a rubber maid, u will enjoy the extra room, it doesnt even have to be that big, and it will be more stable. the hps light can be put in a clear glass tube and vented, very good idea for small grows using hid lights that get very hot, even tho a 150 wont get that hot, hot enough to kill the crop. but it will work. search cool tube and check out some of the cab grows in here, you will get more help reading up on there threads then anything becuase u will have pictures we dont have and explinations we dont need. Most of us, me being one of them have good amounts of space to work with and it seems to be alot different on how much space you have.

good luck brotha