http://gta-worldmods.planet-multiplayer.de...dmods.de%5D.jpg

http://s3.amazonaws.com/vodpod.com.videos....9.medium160.jpg


These are mods for GTA, but would it be at least possible to convert those files into a nif for use in Oblivion? Or is it a lost cause?

It would probably be easier to make them from scratch. Being clothing, they would have to be rerigged to the Oblivion skeleton. Even then, they'd have ridiculously low detail.