cobra front bumper help...

so i finally have the last part of the cobra bumper puzzle. just got the bottom lip spoiler for the bumper, but no fasteners. i went to ford parts dept. and they were not helpful at all, did not have the correct fasteners, and could not get them for a while. what should i use? anyone have some #s on these clips, i believe there are 2 different types, and i have an auto store here that sells tons of those retaining clips, rivets, etc...but i need some info on them...anything would help, thanks in advance.