Brighter bulbs don't dazzle as much as poorly aligned lights - i'd get your light alignment checked first and then consider brighter bulbs. I found the Leons dipped beam to be far too low as standard and not that bright even after it was aligned.
HID will work in your headlight units but you may find 100W bulbs give you the same light output but with less or just as much dazzle.
Leons have plastic lenses so it's quite possible that prolonged use of100W through anything but clean lenses will eventually discolour them and possibly even melt them.
That's why HID is preferred as it burns a LOT cooler than a 100W bulb does.