I converted the Hella Micro DE's to HIDs back in September 2006 :-)
Back then I used to order HID stuff from XenonRider, and I do remember a few years ago people were having good luck with DDM stuff as well. But as you know times/products/prices change and companies don't always keep up. The current HID kit I am running on the fogs is amazing, the ballast/ignitor box is actually a very small black cylinder, found them on eBay.
The newest HID kit from V-LEDs has the most compact high quality ballast/ignitor that I have ever seen. These are not just slim, they are pocket sized almost like a credit card small.