Hi Jay,
I have Pavão's from Ginetes on my mother's maternal side. Don't know if it will help you in your search, but you can check her tree here:
http://trees.ancestry.com/tree/31607942/familyI think normally you would have to go back until about 1860 at which point you can order the microfilmed records of the church of São Sebastian (Ginetes) where you will be able to work backwards and do a thorough search of your ancestry.
If you don't have the info to that point where you can order the film, i would suggest perhaps using the services of a researcher to get you to that point. Than order the film. I have used one named João Ventura (
heroi99@yahoo.com) who helped me get to the point of being able to order the film and my research took off from there.
Best of luck to you on your search.