I think you would be floored by dual ULS-15's in a room that small...
I have a single F112 in 1800 cu ft room... and that alone is simply amazing, although I would love to have duals to smooth out response, I don't have the room, but it would be overkill for sure....
Nothing like going overkill....
I approve duals... Room Gain with the Sealed in that small room will get you down dam low, and be quite impressive...
