Between the two choices, grab some trekking/butterfly bars. I have a set on an early 90s Schwinn hybrid and they are excellent. Lots of hand positions and angles allow for plenty of adjusting to get comfortable during long rides.
To throw another option into the mix- Scott AT-2 and AT-3 bars. They are on ebay from time to time on both sides of the pond. One of my wife’s bikes has AT-2 bars and they are excellent. They curve on the sides and effectively have built in barends. The AT-3 actually wraps a little more and you can reach forward to extend and effective drop under the wind pretty well. Sorta best of all worlds- flat bars, multiple hand positions, aero position for wind.