CalDirt

Went with Morimoto GM XB LED Fogs. Aside from the faulty connector which you have to rebuild to make it fit, it's plug and play and with LEDs, you don't have to worry about any overheating issues, etc. Light is a nice clean white. They aren't cheap but I'll probably never have to replace them either. http://www.morimotohid.com/complete-headlight-fog-light-housings/morimoto-xb-led-fog-lights-type-gm-h16.html

I think this might be the one you're looking for goblue4106: http://www.gm-trucks.com/forums/topic/171698-mike1220s-slt-sierra-halos-color-change-drls-and-fxr-retrofit-walkthrough/

Hey OldDawg45 - I feel your pain. Been reading up on this for about 2 weeks before I'm ready to pull the trigger. This is the combination of HIDs and fogs that both Morimoto and TRS suggested for a '15: Morimoto Sierra Spec: Morimoto Elite HID System - 5500k KIT The Retrofit Source http://www.theretrofitsource.com/hid-systems/morimoto-elite-hid-system-sierra-low-beam.html http://www.amazon.com/Morimoto-Elite-HID-System/dp/B013N20NSU/ref=sr_1_1_m?s=automotive&ie=UTF8&qid=1442849575&sr=1-1&keywords=9012+Morimoto http://www.morimotohid.com/hid-systems/morimoto-elite-hid-system-sierra-low-beam.html Morimoto GM XB LED Fogs 50374 http://www.amazon.com/Morimoto-Type-LED-Projector-Light/dp/B00XA3C0FC/ref=sr_1_fkmr1_2?s=automotive&ie=UTF8&qid=1442852322&sr=1-2-fkmr1&keywords=Morimoto+50374 http://www.morimotohid.com/complete-headlight-fog-light-housings/morimoto-xb-led-fog-lights-type-gm-h16.html