Halogen lights are designed that the brighter you want the more watts they draw. Not much you can do to get a brighter light with out more watt usage. The white halogens look brighter because there is no tint on the bulb itself. Try installing the lights you have, just to see what may happen. Once installed, turn the lights on while the engine is running and see if the motor changes its idle speed. If the motor boggs down slightly. If so, your drawing too much wattage for the stator to keep up. If not, your good to go...Good luck.
ps. Thats why I went with H.I.D.s
I get 3x the light at half the watts of halogens.