I've been asked to wire a 200A, single-phase 40-circuit panel (i.e., sub-panel) fed from a 200A disconnect. The distance from the disconnect to the panel is 170 ft. I would normally use 4/0, 2/0 direct bury underground conductors. I need to size the wire and allow for a voltage drop. What size do my feeders, neutral, and ground need to be in this situation?