well there are lots of different places you can look. ebay has them (although i wouldn't go for a cheap knockoff), search google, craigslist, or even in the classifieds section of this site or other sites like honda-tech.com, team-integra.net, etc.

ONE IMPORTANT THING: if your lights already dim bc of your system, you might want to also invest in another battery. HIDs run off of a motor that is included with the kit and that will drain your battery even more than your system is right now. it would be wise to invest in a capacitor for your system, or even an independent battery if you decide to go with the HIDs