I would look in Somers Point or any other town that is just outside of OC. In Somers Point, the Crab Trap is an excellent restaurant. I don't think they take reservations, but if you have a large group, they may. It is also a little pricy, so having a large group there could add up quick.
Do you have a rental house or know of anyone who could host the RD at their home? You can have a caterer come into the house and you could provide all the alcohol for the dinner.