HIDs will be the brightest. If you want to take advantage of light output then retroffited projectors or even the spyder auto projectors with HIDs would be a nice upgrade. If you want to keep halogens then any bulb with a blue coating will limit light output. You will need to use the one's with a clear lens on them like the GE nighthawks, philips xtreme etc. You could pair them with a harness to get more voltage to the bulbs from the battery. You could also try higher wattage halogen bulbs with a relay harness.
