4x6 HID's?

[SeanPaintsFlames]

Are they the rectangle sealed-beam lights? If so, you'd have to get a set of 4 of the H4-ready housings:
http://cgi.ebay.com/ebaymotors/82-92...Q5fAccessories

A pair of the bi-xenon HID bulbs with the ballasts:
http://cgi.ebay.com/ebaymotors/55W-B...Q5fAccessories

And another pair of regular HIDs for the "high beams"
http://cgi.ebay.com/ebaymotors/HID-C...Q5fAccessories

I guess you could just get 4 of the same Bi-xenon HID bulbs, so all 4 would be a high and low beam. The only issue you're going to run into is that there is a few seconds of warm-up before the bulbs are really "on", so using a separate set of HID bulbs for high beams wouldn't really let you flip them on and off as oncoming traffic approached until they got warmed up. The BI-xenon bulbs should overcome this.
There was a recent thread on the HID setup somewhere, but I don't know how it ended.