As you take a look at those 500W lamps, check out the color temp of the bulbs. Those flamethrowers will be a dominant light source in your photos. Depending upon the temp of the bulbs, you might wind up with a color cast in your photos. If you go with smaller lights, you can position them anywhere you want. You can put some with lower wattage bulbs to create depth. You can point others at a background in order to absorb shadows. You can even use one as a hair light.