After quite an extensive bit of research on HIDPlanet.com, I have learned that there is really only one way to properly add HID's to the Moss Headlamp Kit. While the Moss Kit comes standard with Halogen Projectors, they are insufficient to properly run HID's. The light, because the projector lens is different, will have hotspotting, the cutoff will not be allighed properly; ultimatly, one will have the HID look but the lighting quality will subpar. In fact, using an HID kit designed to replace the H9 Halogen bulb would probably produce results worse than just using a standard H9 bulb. H9's are really good halogen bulbs.
What needs to be done, though it will be expensive, is the Halogen Projector needs to be exchanged with a HID Projecter. I know, they run about $500 each. Well, that is what needs to be done. After exchanging the module, a HID kit needs to be purchased, though not the ones on eBay. The eBay kits are poorly made, don't last long, and are just direct replacements to halogen bulbs. On HIDPlanet.com, they sell kits designed for those that have an HID projector. Considering you have added the Hella HID Projector module, you can use a real HID bulb, a D2S. All the cutoffs will be alligned, there will be no hotspotting, and it wil shine nice and bright.
It all depends on what you are trying to do. If you are just going for the look of HID, get a cheap eBay kit with a H9 bulb. Otherwise, incour the expense and do it right. When done, you will have a beautiful setup that rivals the likes of a BMW or Audi HID setup.