The clothing system already exists within GTA:SA, but it only works with the CJ Skin (Skin ID 0).
I am not a pro on scripting or something but that script is already exist on SA-MP servers, so maybe it would work on MTA aswell..Basically exactly what he said. It doesn't work with any other Peds other than CJ. Also for things like crouching down it can be really buggy looking to have the clothes/appear follow you
Support
Or alternate idea.
You could just add any epic skin mods. For like 10-20 skins to the server.
Possible for the Skin Idea.
@Weedex SA-MP is a little different than MTA. Like how in SA-MP, the heads of Peds can move, in MTA they can't because of Sync issues. Its kinda the same idea with wearable sunglasses, etc