I would have your SP disassembled and cleaned, removing all of the small metal chips that the factory sometimes leaves in there, and have any burrs removed. Then re-lube and reassemble. I radiused the face of the trigger for the sake of comfort. If you have to install a lighter mainspring, don't go too light. The hammer must fall with enough force to ignite the primer every time! Change the grips if you must. If you have trouble seeing the front sight, try painting it before you replace it. If you find a color you like, you have saved yourself some time and money. This is all I did to my SP.
It is important to remember that these are not competition revolvers. If one wants ported barrels or ultra-light triggers, make that your next project gun. If your SP is ever is ever taken as evidence in a shooting, you want it to look like any other SP. You do not want the jury to think that you are obsessed with guns and had a special "killing machine" made. In a murder trial I was involved with, the murder weapon was passed from juror to juror; and they were instructed to examine and dry fire it to feel the trigger pull.
Keep your SP as close to stock as possible. Practice, practice, practice. May you never have to use it.