Room for 25 - 30
If it's privacy you're looking for, Abigael's has private rooms of various sizes downstairs that offer much more privacy than the upstairs.
Solo also has private rooms, but I believe there's a pretty sizeable fee for reserving them. They have a semi-private seating area off to the side, too, which I think you can just reserve with no fee and is about the right size for you.
The upstairs at Le Marais has leather club chairs and its own bar and is probably about the right size for your group to take it over completely (and there's no rental fee).