An extended slide stop can be purchased anywhere from $10-$15. It is quite simple to replace. Have you ever performed a detail strip of your frame? Regardless, here is a vid.
http://www.youtube.com/watch?v=NQbYqWBLa9w
Personally, I don't see a need for the said. However, many people do.
With regard to the aftermarket guide rods . . . At one time, I swapped out my factory recoil spring/guide rod assemblies for aftermarket ones. Eventually, everything went back to the factory configuration. I didn't realize any productive benefits.