I was told you don't want to put HIDs in the stock housings, For a few reasons. 1. Light pattern. Since the HID bulb is brighter and more different, It will scatter light all over the place and blind oncoming drivers and not even be good usable light!
2. The heat (From what I heard, dunno for sure) from the HID bulbs could melt the plastic housings of your stock assemblies.
If you wanna go true HID, All I can really suggest is finding projection housings that are meant for HID systems. Otherwise, Going with better halogen bulbs, polishing the lens and getting them aimed right is the only true way to get better light output.