Dan,
The one pictured is the Bisley style. I have one that does fit the new re-issue flat tops, but it was made specifically for them. (Also fits New Vaqueros). The one in the catalog link that you shared fits "standard" full size Blackhawks/Vaqueros. If you are asking about the Bisley style it won't fit.
I have not purchased any from Brownell's. I know Power makes them to fit the newer medium frame guns, just not sure if they are in the Brownell's catalog or not.
As for experience with them, I have several of the Power half cock hammer and trigger kits. I really like them a lot. The biggest advantage in my opinion is the trigger pull. It feels as good as any custom job I ever had done. The quality of the parts is second to none also.
Hope this helps.