Technically you don't need a projector to run HIDs (although I have been on that bandwagon before), but you do need a housing that was designed with proper optics for HIDs. Just tossing a set of HID bulbs into your stock housings is a crapshoot at best, and very dangerous at the worst.
Do yourself and your fellow motorists a favor and do the HID conversion right, or not at all. If you don't like the projector look, then you can cut the back out of your stock housings and insert the projectors into them.
Here's a stock Jeep housing, with a Lexus projector retrofited:
Here's the pattern from that Jeep before the projector retrofit:
...and after the projector retrofit:
Obviously this will vary depending on the housing you are starting with, but it just goes to show how much of a difference it makes.
- Justin