Whether you are using brand new or used headlights you just need to make sure that the housings have a good pair of bulbs and a good pair of ballasts. (If you purchase at the dealer you will definitely get a complete headlight, if you don't know what all you need then buy them from here: WK2 Bi-Xenon HID Headlamps
With the harenesses the equation is like this:
OEM bi-xenon headlight (complete) + retrofit harnesses = plug and play installation
It sounds like you would like to add DRL's?
For this additional parts are needed:
- Two MOPAR wiring repair kits for DRL connectors (part # 68030096AA) this kits retails for $40 and you need two
- An aftermarket DRL relay harness
I was trying to put together a more affordable DRL connector kit but it was not working out, the quantities required for an order was a crazy amount so for now mopar is the only source I know of.