I wanted to buy a new headlight for my 97 zx-6r. it's a single headlight, and an H4. I was looking at the Sylvania Silverstar. It says " For Motorcycle Use Only". It's only like 10-20 bucks. then i look in catalogs and the PIAA H4 is 45-50 bucks. whats the big difference? is the PIAA that much brighter? what brands do you guys use? also, my bulb is 55/60W. do i have to buy that wattage or can i step up to the 90/110?