Adding auxiliary lamps can be problematic as most aren't autoleveling. Do you have HID headlights now? Not sure which models have them as standard or optional. Those generally are much better than the stock lamps.
Check out
www.hellausa.com . They have a visualizer that shows the light pattern and throw from a bunch of their add-on lights in various bulb types, including HID, LED, and halogen.
Adding higher wattage bulbs to your existing headlights may work, but higher wattage means more heat, and that can be a problem, too - you don't want to melt things.