Well it's going to depend on how dense the shade is under those oaks. If the shade is very dense, you'll have a difficult time growing anything large enough to provide privacy under them. You''ll need to have at least 6 to 8 hours of sun to grow most screening or hedge plants. You can go to our Plant Encyclopedia on this website and do an ADVANCED search which allows you to plug in a host of different planting criteria. It will then give you a list of plants that might work.