First of all, i want to say this website totally rules

I have a 56 Astra 1.6 Sxi sport hatch. I would like to know what the difference between HID and Xenon is? And also I want lights fitted that are very powerful and emit a very bright blue light. Can anyone tell me what Xenon kit to buy from any website such as Ebay. Also feel free to post pics of your Xenons i'd like to see some for myself. Thanks