Unsure what exactly you're on about, there is a HUGE difference between the Chinese HID bulb/ballasts kits people put in Honda's and blind people, and actual HID's from the OEM. Your top post mentioned wanting to install OEM HID assemblies in your Halogen equipped assembly, so I will assume you want to do a proper OEM retrofit. It's quite easy parts-wise, you will need L and R OEM Headlight assemblies which include bulbs and ballasts) not super cheap, but excellent pieces, and then you will need the Ford front light wiring harness, this includes the wires and plugs for the headlight, horn, turn signal, parking lamps, and since you have a GT500, intercooler sensor. This harness is different than the Halogen harness in the sense that it includes a relay box that mounts on the Passenger shock tower (google engine bay pics of Halogen and HID GT500s to see this).
Those are mostly the only parts. The last change you'll need to make is to jump two wires in that new harness with a Zener diode to limit current since HID's draw less amperage and have a polarity unlike a halogen bulb.
I did the swap in my 2009 back in 12 or 13 and it's wonderful. PM with additional questions or for the instructions of jumping the harness I may still have the PDF