I had a Moyers after-market trigger put on my Ruger 1V and it works pretty good.
They are, I'm sure, available from MidwayUSA or direct from Moyers at:
Moyers Gun Repair
2370 Sunset Strip
Mountain Home, Idaho 83647
Midway, I think, is cheaper than direct from Moyers, although he will do the installation for you for $10 (with, of course, shipping both ways extra).