Adding the lights themselves is doable, but having factory functionality is another animal. That feature is controlled through the BCM, so unless you can source not only the fog lights, but also wiring harnesses, fabricate your own mounting brackets, or buy a bumper with the fog light mounts in it, headlight control switch with the fog light button in it, and get your BCM reprogrammed somewhere for the added feature...
... a less than factory setup may be easier to put together, and more cost effective. If you're handy, you can rig up your own wiring harness through a relay, and put a switch in the cabin to activate them. I think someone posted how they made fog light mounting brackets somewhere...