I don't know soil that well... but I think soil ph should be around 6.4 or a little higher. MH and HPS are what's known as HID, High intensity discharge. THey are the ones that light parking lots. MH is 'white' looking and used for vegging plants. HPS is 'orange' light and used to Flower plants (make buds). LED's are expensive and not proven. CFL's and Fluoro's are the small alternatives to HID lights. They give less light, produce less heat, cost less in electricity... but give you less herb. HID's are kinda hard to work with becuase of the heat. One other thing. You can get a ballast that switches between MH and HPS... or you can get a HPS ballast, then buy a MH bulb that runs on it so you can have both kinds of light from one ballast.
So like you want to grow a plant "Inside" a 55 gal drum. You can totally do that. People grow in a desktop computer case, and mini fridges. Might want to use a screen to keep it short, or LST/ suppercropping.
