Based on the ages of your kids you have 5 people that can be counted towards the room - DH, You, DD9, DS6, DD3. The younger 2 don't count as they're under 2.
Now my personal opinion: you can probably go with a deluxe that has 5 occupancy limit or a moderate like POR with a trundle bed. I really don't think you want to stuff everyone in a value or any other room that only has a 4 person occupancy, not only because Disney won't allow it, but the rooms are fairly small and you could get quite cramped.
If you can swing a deluxe, most of them (except WL and AKL) will have a daybed on top of the 2 queen beds so you can fit 5 people plus a couple of cribs/playpens. It could get cramped in there, but the Contemporary's garden wing rooms are pretty big and I can see putting everyone in there.
Another option to consider is renting DVC points from a DVC member here. That way you may be able to swing a bigger room. If that's not possible, then you may have to go 2 rooms at a value or go off-site and rent a villa.