Thank you for contacting me.
As per your questions:
1) retrofitting your headlights with a projector would require you to literally open up your headlights and modify them to accommodate an HID projector. We do sell HID projectors, shrouds, and HID components for this task however we do not perform retrofitting services.
2) Vehicles that come with HIDs from the factory use 4300k HID bulbs. I would suggest going with a 4300k HID kit if you want to get the most OEM functionality.
3) The 2012 Cherokee uses an H11 bulb for the low beams meaning that you would need to order an H11 HID conversion kit. Installing an HID kit
on your vehicle require the use of a relay harness (included for JeepGarage Members). Furthermore, you need an additional component CANBUS fix
to prevent any flickering.
4) The Cherokee uses a 5202 bulb for the fog lights meaning that you would need to order a 5202 kit to perform this upgrade.
Take a look at this write up on how to install an HID kit on a 2011+ Jeep Cherokee