I think I have a couple of leads for you. I have, Antonio de Sousa Gois or Goes cc Ana Maria do Sacramento, Vila Franca Matriz; The paternal grandmother of this Ana is Ana Moniz cc Bento Cardoso da Silva, in Ponta Garca, March 18- 1695. So this may be a match.
I also have Manuel de Sousa cc Escolastica Rosa, married in VF Matriz, Aug 4- 1782. Said Manuel is stated to be native of Fenais da Vera Cruz and his parents are Antonio de Sousa and Ana Moniz.
Since you have already looked in Vila Franca for children, maybe start looking in Fenais da Ajuda (aka Fenais da Vera Cruz). Or even for the marriage.
Hope this helps.