I downloaded both APM and UCAC3PS. APM has an installer and SGP sees it with no problem. However, I extracted the UCAC3PS files, point SGP to that directory but it doesn't recognize it. Says no catalog files there. Tried their default directory and my own and still didn't see it.
NEVER MIND - Discovered the problem. When I moved the folder/files to another directory, for some reason the INDEX file failed to move. Once I moved all files, was good to go.