Not so sure about what you mean by stock heatsink, but the LED heatsink in the Ultrafire is flat, which is unsuitable for laser diodes. LD heatsinks need to be a cylindrical prism with a hole in it for the module.
You "can" use the two heatsinks you first posted but you'll have to find a way to secure it tightly in the host. What you could do is either send the host to a machinist to have a custom heatsink made or measure the dimensions yourself and get a heatsink made.
Again, use the two links I posted to get one made.
With the Ultrafie C3 host it is possible to use the stock reflector as a heatsink. You need to drill the hole out to fit the module. I think Lazeerer did that once