I would like to have a Patridge front sight on my .30 Carbine Blackhawk. I have not found a company that sells an interchangeable front sight assembly. This surprises me a little.
Looking on the custom gunsmiths web sights I see many example of Patridge and modified Patridge sights, but no replacements for "duffer" installation.

Has anyone installed one of the the Bisley grip frames from Brownells on a Blackhawk yet? I have a .32 Mag Bisley and converting the carbine seems interesting.

Don't know of any "do it yourself" kits to replace your front sight, but any competent  gunsmith could do the job for you.

As far as the Bisley frame conversion, it can be done on any New Model Blackhawk with no modification, and can be done on Old Models with a little know-how. The only problem you might face would be having the grip frame "match polished" to match the dimensions of the cylinder frame. The Ruger Single-action revolvers with steel grip frames must have the grip frame mounted to the cylinder frame and then polished as a unit to get the sides of the frames to match up.

You can also buy the Bisley frame from Ruger, but they won't install it on your Blackhawk unless it left the factory as a Bisley. Don't understand their reasoning, but that's what they'll tell you.

Good luck!