I am sorry for this delayed reply to your gardening question. We are transitioning to a new Q&A system and your question was unfortunately lost in the transition. I have discovered it now and hope this reply is not too late to be of help.
Weeping yaupon is okay but is not very dense and as such would not be much for privacy. I think your best bet is a Bright 'N Tight Carolina Laurel. It is evergreen, the right height and listed as tolerant of the seacoast exposure.
Thanks for the question. Please stop in again soon!
Q&A Library Searching Tips