I tried dealing with Daniel Stern and after a quick initial reply via email he never responded to any of my follow-up emails and I could never reach him on the phone. After three months of this I got a lead from a forum posting (I think it was here) about Bosch H4 e-codes from BusDepot.com (a VW bus site).
I bought a pair of the Bosch lamps for around $80 at the time. Just looked and you can get them for $45 per set now. http://busdepot.com/details.jsp?partnumber=0301600118
. Used Silverstar Ultra bulbs and made my own wiring harness (this was the toughest part, because I also re-wired my roof lights and pre-wired for a bunch of other lights I have planned). Aiming them was also a bit of challenge, but not too bad.
The light from the Bosch's and the Silverstar Ultra's is noticeably WAY MUCH better than stock. Much better, even, than the stock lamps with Silverstar or PIAA H13 bulbs (which I tried first). The light is bright and pure white (no blueish tint) with great distribution. Much better reach with both low- and high-beams, and with that E-code cutoff I never get flashed by oncoming drivers.
Maybe the Cibie's are better, but I don't see how. At $45 for the pair, that's less that 1/3 the price of the Cibies and IPF's, and less than 1/2 the price of the Hella's. You can make your own H13:H4 adapters or just cut-off the H13 plug and solder on H4 plugs on your factory wiring, which would be OK as long as you use the same wattage bulbs as stock. But you'll get much better (whiter) and brighter output if you add relays that trigger off the stock wiring then drive the headlights directly off the battery using at least 14 AWG (I used 12 AWG) wiring. Note that you do need to add a capacitor and diode to the relay inputs to deal with the PWM signal caused by the JK's CANBUS monitoring, and using waterproof marine shrink tubing and heavy-duty relay sockets and H4 receptacles is recommended.
As mentioned above, if you use the OEM wiring you should not get any complaints from the computer as long as you use the same wattage bulbs as stock. The computer should actually be fine with any wattage bulbs, as it seems to only care about shorts or opens (i.e., you will get a code recorded -- but no check engine light -- on the unused OEM connector after installing your own wiring harness; it is harmless). Going with higher-wattage bulbs is a no-go due to the already insufficient OEM wire size.