CDR, you can get the pull made somewhat lighter, but the most important thing is to have it SMOOTH. With the relatively long, heavy pull on a double action revolver, it's also important to use a really firm grasp to stabilize the gun against the pull of the trigger finger.
I can personally recommend Rick Devoid for SP101 trigger jobs, at www.tarnhelm.com
. He's done an SP or two for me that came out awfully sweet and 100% reliable, and he has done a lot more of them for my students, and I'm still waiting to hear the first complaint.
Best of luck,