this is kinda off subject but im thinking about buying a pair of H4 bulbs that's really white and kinda look like those HID on Mecedes. PIAA bulbs any good?
I bought mine at Auto Zone, but I assume you can get them from www.eurolite.com. They are the Xenon bulbs. Very nice. Try some other places around the web, not sure on what car you got though.
Most replacement bulbs you can get aren't any brighter than stock bulbs -- even the ones that say "HID" all over them, and especially anything you'll get at AutoZone. The only difference with these bulbs is that are bluish instead of amber lights.
Almost every H4 bulb you can get is 55W low beam and 60W high beam. If you look, though, you can find 100W/90W bulbs.
I got some 100W Xenon bulbs at www.globalpremier.com. They run a lot of eBay auctions. Make sure you get a set that says "High Wattage" on it. It's $18.99 for a pair of the XD3's that I got. I don't think it's worth paying extra for the other ones -- they're all 100W bulbs with a bright bluish light.