I replaced my valve covers with a aluminum covers from Tarret because I had the old painted ones and the paint was bubbling off.
http://www.tarett.com/items/993-964-products/billet-aluminum-valve-covers-for-911-964-993-valve-covers-detail.htm
If you have a small oil leak, you might want to try replacing the gaskets first. You can get a complete gaskedt kit from our host for much less the new valve covers