im pretty sure 100w is way to high, you definately run the risk of melting things. just get some silverstars, or upgrade housings and get some HIDs.
SilverStars are a brand of bulb. You can pick them up at Wal-Mart, Autozone, PepBoys. Anwhere like that will have them. Should be about $50/pair (I think??)
100 watt bulbs will melt your harness, unless you buy an adapter harness. http://www.suvlights.com/ has some pretty good deals on that type stuff.