I'm planning to rig my boat with lights this spring and am looking at the HPS units. BE has 70 and 150 watt units for sale. How much light would 4 of the 150's or 6 70's put out? Do I need to add extra gen wattage for startup of these lights? Can I interchange the bulbs in these things? They should really help with generator needs. Does anyone know of a good link for all these questions. Thanks much for the help.