Get a Cheap Light System Here

Cheap is right. How are you supposed to vent the heat? You need an exhaust fan. The reflector that the blub fits in should have a piece of glass that goes between it and your plants. That allows the exhaust fan to suck all that heat away. Which will build like you won't belive in a small space.

Those are good prices indeed....

what is the general rule for number of watts per square foot of space.


and also... HPS or the MH conversion bulb?

General rule is 50w per square foot. Some people just use a HPS, but if you wanna achieve best results use a MH for veg and HPS for flower.