I have a 2008 XLT with the grilles in the bumper (no fog light option). They can be removed and replaced with the fog lights sold by Tasca Ford. I bought mine on
Tasca sells the replacement headlight switch with the pull out feature for the fog light if you want to go that route. Tasca may be cheaper than other Ford dealers maybe. I'll probably just wire mine to a relay and separate switch.
First I ordered a set of Chinese Depo brand fog lights but they were the wrong style and after searching the Depo web site, I could not find any that fit so I just ordered them from Tasca.
I found a pig tail wiring kit at O'Reilley Auto parts that fit the Sylvania bulbs that came with the Ford fog lights. The bulbs are 9145 and the pigtail says it fits 9005, but they are the same connector.