Lockheed P-3 Orion
You may even be able to get away with smaller motors. I think I remember a large C-130 model (Skip Mast?) that used 4 .20 or .25 size motors. I agree with the torque rolling - you'd want motors that were reliable more than anything else. And the ability to turn a reasonable looking prop, diameter-wise. You could even have it pop out little fake sono-buoys!
I had seen photos somewhere of a Japanese operated P-3 with a really unusual color scheme, if I remember correctly...