I'd be really careful about getting a trigger job on a .22. I have two 617s, both of which I bought used. One of them has an absolutely delightful trigger, light and smooth. Someone obviously worked on it. The problem, however, is that I get misfires, every 20th or 30th round when firing double action. My other 617 has a factory trigger. It's heavy but smooth. No misfires. I've decided that I'll have no work done on it given the risk of developing light strikes with tempermental rimfire ammo.
Btw, I recently spoke with someone at Smith about trigger jobs on 22s. He said Smith won't do them on any model, new or old, due to the likelihood that lightening the trigger will cause light strikes.