Due Amici in West Orange is a BYOB Italian that serves very good food. They have a large 2nd room, but I doubt they would make it private on a Saturday night. Avenue Bistro in Verona, has a bar and good food. They also have a 2nd room. Not sure if it is small enough to dedicate to one group on a Saturday evening. Primavera Restaurant in West Orange also has a liquor license. Not sure if it has a private room but I would think it does since it's connected to a Wilshire Grand Hotel (maybe some of your guests are staying there). They may not fall into your price range. If I think of anything else in the area, I will let you know.