Didn't see this post until Sunlit PM'd me
There are 7 parts required to add STOCK foglights to any of our OBS rigs.
1) Bumper: GM pn 15680830 is chrome smooth(no bumper guard or strip holes) LMC sells other options but the holes are not aligned and my LMC bumper shows signs of rust after less than 12 months on my truck
2)Fog Lamps: 2 required p/n 12477563; available aftermarket or Ebay
3)Fog Light buckets(NLA);
left is p/n 15045495
right is p/n 15045494
4) Fog light switch for vertical position p/n 15738877 (NLA) found occasionally on Ebay. If you go into the horizontal position; usually used by the push button 4wd system, the fog light switch is 15687022, again Ebay is your best shot for this.
5) Switch bezel plate vertical mounting, PN varies based on 1 hole 15694888(barn doors w/fog lights) or 3 hole 15696254( tail gate, wiper and fog light). If you go into the horizontal position, 1 hole Bezel is 15696260
6) Interior harness (NLA from GM) p/n 15743770 was available from Vintage parts
7) exterior harness(NLA from GM) p/n 15045442 was available from Vintage Parts
An option to the two GM harnesses is a single harness option from EBAY; Search on your year tahoe fog light harness. I haven't used that so I cannot vouch for it, but it looks like it could/might work. Item number 160492876415 is currently on Ebay and looks like you send your switch to them and they wire it up and send back a working harness/switch combo.
Let me know if you need further help.
Tbruz