Hey Ben, the way I had planned to do it and avoid the 'lamp out' light was to swap the fog light and main headlight circuits. The fog lights are not part of the system that the FCM (Forward Control Module) monitors. Just the headlights, front turn signals, taillights, and brake lights are. You will also notice on your truck I added a separate relay under the dash for the foglights. I also ran wiring out to each foglight using 16 gauge wire as opposed to the facotry 20 gauge, and just tucked the OEM harness out of the way. Originally, I had 9006 HID lights in the fogs, and they worked great. A ballast ended up not being sealed correctly and failed, which is why I took everything out. After all, I was going to sell the truck soon anyhow. So all you need to do is use the wiring I ran to power up your HID lights in the main headlight housings. Connect the old OEM headlight wiring to the foglights, and you should be all set, complete with no 'lamp out' light. You would, of course, need to fit the 9007 headlight bulbs into the 9006 foglights.
Another option is to buy the Mopar accessory foglight switch, and use that to power the OEM foglights while using the original foglight switch for the HIDs. THe accessory switch is pretty cool, lights up and even has a foglight icon on it. Then all you have to do is plug bulbs in the factory wiring for the main headlights, tuck them away behind the housings, and remember to never turn them on.
One other thing to keep in mind. The main OEM headlights use a PWM signal to illuminate, and some guys have had problems powering up a relay off that circuit. I read about a guy who installed HIDs a while back and used the factory headlight wiring to trigger a relay. He did not know about the PWM signal. The relay would turn on and off so fast, it was not detectable, but he kept on going through ballasts. Turns out they don't like to be turned on and off dozens of time each second! You would need some sort of solid-state circuitry to use the factory headlight wiring as a trigger.