Thanks... I was looking through them and found that exact picture (or at least one that was very similar). So, I deleted my question. But I appreciate you answering. =)Ebay is your best bet. Just look at the pics of the back/bottom of the housings. The ballast for the HID is on the bottom. If it doesn't have that then its halogen.
Most will specify halogen or not in the description though.
This is something I will have to keep in mind before doing a retrofit, but I am still very interested in doing the mod.