There are several handlebar measurements. In particular reach will vary somewhat, and the width of the bars.

See some notes here:
https://www.bicycling.com/bikes-gear...andlebar-guide
https://www.artscyclery.com/learning...ebarwidth.html

I'm not sure about the rationale for handlebar width. I like somewhat narrower bars, and the first article above suggests that too wide of bars can cause shoulder stress.

The new 31.8 stems have an open face, and are easy to swap. Your local bike shop (LBS) may have some swapped stems that they'd allow you to experiment with, or a local bike co-op/recycler might have a pile of them that they'll sell for cheap.

I'd probably start with the stem identical to what you have as a baseline, then experiment from there.

I find the new winged bars to be comfortable for riding from the tops, and the compact design puts the brake hoods in a comfortable location. There are many brands available. Try a few different grip positions including grabbing the tops of your brake hoods and laying the forearms across the bars. Riding with one hand? Most people can get to the brakes quickly from any bar position, although interrupter brakes are popular with some riders for riding from the tops.