The type of safety the RIAs has will have a lot to do with how you set up grips or it. The two I've had didn't have the tab that went behind the grip panel And I had to reshape the top of one grip to alklow for the full travel of the safety lever. So I wouild look at the grips on it now and htat will help you in your search. Being some materials are better to work with than others it might be big factor in what you wend up with.At any rate to cut them to fit any of the two types of ambi safeties is pretty easy work and one of the few times I'll use a dremel near a firearm. It's pretty easy to reshape the top or make the cutout on the back depending what you need.
Any 19011 grip wioll work as far as the holes lining up though....
The tree of liberty must be refreshed from time to time with the blood of patriots and tyrants. Thomas Jefferson
Check out the Pachmyer grips at BassPro. They have a set with finger grooves and hardwood trim around the rubber portion. They are gorgeous and the price is good too. 29.95. I bought a set for my RIA 1911 and they fit and look great!