@Gulfcowboy: I'm excited for you. Your 4 inch, .357 SP101 will make a fine trail field gun for you. I have a 4 inch, .32 H&R SP101, and a 2 1/4 inch, .357 blued steel SP101. I bought the shorter barreled revolver as a sort of "kit" gun. I wouldn't want to part with either revolver.
As for the trigger work, my advice is: "What Pahoo said". The modular design and construction somewhat limit what can be done to improve the trigger. The most improvement can be done by simply changing the hammer spring and the trigger return spring, and you do not necessarily need a gunsmith to do that. As "Pahoo" noted, there are many youtube videos which can walk you through the spring changes if you have a modicum of mechanical ability. The factory hammer spring is 14 pounds and the factory trigger return spring is 10 pounds. Wolff sells a SP101 spring kit, which contains an 8 pound trigger return spring, and 12, 10, and 9 pound hammer springs. Midway shows the wolff kit as out of stock, but wolff shows them in stock on their website. You could order them directly on-line from wolff for about 10 bucks (if I remember the price correctly). I used the 8 pound trigger return spring, and the 12 pound hammer spring. I did not install the 9 or 10 pound hammer springs because people have reported light strikes and misfires from the lighter hammer springs. It did not seem to me that trading reliability for a lighter hammer pull was a good bargain. I have had NO misfires with the lighter 12 pound hammer spring.
There is also a trigger return plunger which travels in a .250 inch diameter hole in the trigger/triggerguard assembly. On both of my guns it looked like the hole had been drilled by a rasp. I de-burred the hole, and then polished it with some very fine jeweler's rouge. The plungers then travelled smoothly in the channel. Whether that helped or not, I don't know. Again, all these things are usually covered in the youtube videos.
Some people will also shim the hammer on the SP101, in order to prevent the hammer from dragging against the frame. You can get SP101 shim kits from "TriggerShims.com". However, I haven't done that. I don't know if hammer shimming is worth it, and so I may or may not do that sometime down the road. In any case...Lucky you! I know you will enjoy your new revolver.
