The higher your hands get, the harder it is to maneuver at low speed ( turning the bars, and not tilting the bike ) because your external arm goes up and your waist has to follow the shoulder movement. The closer you bring your hands together, the more fatigue you will get in your back shoulders area, but you will eventually strentghen out.
IMO, if you go with bars that has a rise in them, you might want to have to lowest risers. I.E.: 3" Risers + 7" Rise Bars, or 1" Risers + 10" Rise Bars.
