I believe the wiring harness, relay and switch are the same for the Cobra fogs as they are for the GT/Mach 1 fogs. The pigtails are slightly different as the bulbs are different than the regular fog light bulbs.
I would recommend picking up the proper pigtails from Latemodel Restoration or somewhere..they aren't very expensive and will save time/headaches down the road.
Below is a link to VMP's page with a full fog light install write up. The wiring portion should be identical for both Cobra fogs and regular fogs.
01-04 V6 CLEAR GT Foglight Kit: VMP Tuning - Superchargers, Tuners, Custom Tunes, & Performance Parts
Keep in mind also that the cobra bumper will fit much closer to the stock v6 bumper. You may have to relocate the bumper top posts back ~.5" or so to re-clip the bumper for better fitment between the hood and bumper.
12 Black GT500 SVT PP l VMP TVS l JLT123 l O/R X l 28x11.50Rx15 M/T Street R's l BMR Suspension l Recaros
03 Sonic Blue 3.8 / 17 Magnetic Fusion Sport 2.7 EB