I plan to scope one of my GP100 sixguns, to deal with the aging eyes. The mount will probably be a Weigand. I may even equip one with an optic mount and an Aimpoint Micro T-1 to be a "war bag" gun for use at work, though I will have to be discreet about it, and put the iron sights back on for the annual qual, due to PD rules against optical sights on duty/back-up handguns. (I do use a P229 in the duty holster, but have often carried a sixgun in a bag/case as a mega-backup; I still shoot a medium/large DA revolver better than any other handgun I have tried.)
For HD scenarios, I have noticed that when I put light on my target, the iron sights are seen in silhouette, which sharpens them a bit. Of course, at HD distance, sights are really not needed, once one has the hang of where the sixgun points.
Edited to add: A Bowen Classic Arms rear sight, perhaps with the rear notch filed to taste, is an option I may also try. One of the sight blade options for the Rough Country rear sight is a blank blade that can be shaped to suit the user. I am about to try a .156" rear notch sight on a 1911, but the maker, 10-8, does not make sixgun sights.