I noticed that my hand was getting thumped a bit right in the web area of my strong hand, after a slight change in the way that I gripped the gun I have not had much trouble since. Keep in mind that I am a long way from being good enough with a wheelgun to offer too much advice.
I use the factory wood grips that came on my 25-2. They feel a lot better to me than some of the smaller ones I have tried. They are still smooth like the Miculek, but not as pretty. A guy in our club makes some grips for his Smith revolvers that feel great and look really good too!