There may be some specific versions or maybe some "special runs"of a model. However, I don't think there will be many of these. A lot of folks don't like them and they add expense. Those that do like such things probably differ a lot in the exact sight they want.
Jim's Rules of Carry: 1. Any gun is better than no gun. 2. A gun that is reliable is better than a gun that is not. 3. A hole in the right place is better than a hole in the wrong place. 4. A bigger hole is a better hole.