I've never done a swap but, about a year ago I looked into it. The price was still alittle high for me. What I did do was swap to some H-4 bulbs, rewire for more power and upgrade to 90/130 watt Xenon bulbs. You talk about a night and day difference.(no pun intended) Huge upgrade for about 130 bucks and a little time. Still not HID's but, much better. One thing that I found at the time was that the HID's only had one bulb for either low beam or high beam but, not both like our lights are supposed to have. There may be such a thing now but, like I said this was over a year ago.
Let us know if you find anything real good. I would still like to upgrade mine to HID's if I found the right parts at thwe right price.