With the amount and type of night driving I do, no one understands the need for better lights than myself. I have put Euro lights in the cars I drive most.
Putting high wattage bulbs in US lights is not a good idea IMHO. Not only are you taxing the wiring and sockets that were not designed to handle the additional current and heat, but the effectiveness of your headlights is much more greatly effected by the reflector shape than the bulb brightness.
If you need better headlights, changing to Euro headlights is the only practical approach. Again IMHO.
Best of luck,