well i used Meguiars Scratch-X for the first time yesterday, and i was very impressed. It wont remove deep scratches, but surface scratches it can handle.
As for touch up paint. I got a can of spray paint color coded from Advanced Auto, and it matches perfectly. I think you can little bottles with a little brush, from Advance too. I never used it so i can't vouge for quality.
As for finding your color code look on your RPO code list (on your spare tire cover) and check this techinfo article to find the paint code http://www.bonnevilleclub.com/forum/...e=article&k=98