I'm doing my very first grow-box for 1 or 2 plants. Now that I've designed the box and ventilation am thinking about lighting. I was thinking of 150w HPS light but they seem to be slightly out of my price-range. I know that CFL are much cheaper and that they make bigger than 40w bulbs. For 1-2 plants what is an optimal amount? How many fixtures and how many bulbs? To get close to a 150w HPS?