At a little under 6 foot, I'm surprised you need that wide a bar. 46 is about the largest common size many places carry. Search and you'll find other ways to measure. Most people concerned about speed go narrow because you reduce aero drag with your hands and arms closer together. Too wide you are are like a kite.

That's a great price on those bars and stem. The list is close to $250 plus tax and the adapter.