So the casinos are filled with men and women wearing all types of neat clothes yet I have never found them in a wardrobe, store or anywhere for that matter. You can certainly kill the person and get them, and take the rep hit for it, but has anyone found anything but the typical FO3 clothes hanging around anywhere?

open console `
select npc
showinventory

get a list of what they have and write down the code numbers

then enter player.additem (code#) (1) where 1 is the number of duplicates desired.

example player.additem 0003831e 1 that is a made up code number just for example
this will put one of that item in the players inventory.
no need to murder em and it is the only way to get the gear to wear for your player short of a mod created with the items available via non console means.

have fun.