A friend of mine showed me an old, old gunsmith's trick for smoothing up a Smith & Wesson trigger. He put a small dab of toothpaste, the baking soda kind, on all the mating surfaces of the trigger, hammer, etc. and then sat in front of the TV, dry firing it in double action for a few hours.
After that, he cleaned all the residue out, lubed it up with Lubriplate grease and put it back together.
Smoothed up the trigger quite nicely, and didn't cost anything but a tiny dab of toothpaste and some time.
If you also want to take about 3lbs off the pull weight (which is typically 12+ lbs), you might want to look at the spring/firing pin kit offered by Apex. I just installed it in my 642, very pleased.
Wolf makes springs for the j frame too. I had it done to my wife's j frame at a shop in CC, TX. I think I could've done it myself but it cost me 50$ including the springs.
The toothpaste idea sounds good too. I'd feel safer doing that than trying to sand parts and possibly changing angles/geometry and screwing up a gun.
I admit I was a bit hesitant the first time I knocked the sideplate off of one of my Smith & Wesson revolvers, but after my friend walked me through the process, it turned out to be pretty doggone easy to take everything out, give it a "once over" and put it all back together again. One thing you'll definitely need is a Smith & Wesson Rebound Slide tool. That little sucker makes assembly and dis-assembly a snap.
Changing out the springs out yourself isn't so bad (IE I did it and I am mechanically challenged) but I can understand wanting a professional to do it. Mitch had a suggestion for a gunsmith that sounds good, in fact I may check out this 5K too. There is also a good revolver man down in Comanche at LSG.