You can get very bright bulbs for the light fixture but you'll want to use LED if you want it as bright as an old-fashioned 100-watt bulb. Bulbs in this fixture must use 60 watts or less and LEDs use a lot less energy to make a lot more light. You can get E12 LED bulbs at the hardware store with a lumen count of more than 1500 lumens and that will be plenty bright enough to replace what you have and only use a few watts each. Check out this helpful article on watts vs lumens here.