Actually Hid is bad in foggy conditions , if you really want to use them in fog then you should get Yellow colored bulbs put in the fogs, Or apply yellow tint paper on fog lights.
If you still want an HID kit (Nothing wrong with that), local markets are full of them (All Chinese) ranging anywhere from 3k to 15k.
A decent 55w Hid kit should set you back 5.5k with 1 year warranty for ballasts (Or Blaster in local language) .
In Rwp i'd recommend Heera Brothers in Saddar Rawalpindi.