What if you put aero bars on the moustache bars? It would look like a frakenstien handlebar setup, but if your not too worried about that you could have the moustache bars for the climbs and the aero bars for a change up, flats and downhills. You would have to have moustache bars with a long enough straight section, and the aero bars might be too close up if you have a shorter stem because of the moustache bars.

I have a long commute, and I need an upright position for about the quarter of it goes through an urban setting and requires an upright position, but aero bars to help me get there would be great.

Just a thought.