Which hammer for a Model 10-9?

[spanishjames]

I want to bob the hammer on my S&W Model 10-9, but I'd rather cut a replacement hammer and keep the original in case I want to change it back someday. Does anyone know if a 10-7, 10-5, or any others will fit a 10-9?

Should I get the hammer and trigger? Or do I only need the hammer?

Any help would be appreciated.