Just be sure they're street legal. Don't mess with "HID" retrofits.
You mean aftermarket HID kids. A HID retrofit is highly recommended and is required if you want to be street legal and not buy new headlights. A retrofit is installing HID projector lenses in to a halogen housing, with the end result being a street legal HID setup.
I've ordered a retrofit from this guy, just waiting for the headlights to come back!: