I've availed myself of Mag-na-port's shotgun service (Pro-Port) on two occasions (12-ga pump and 10-ga auto) and have been happy with the results and service. I, however, don't have any first hand experience with their handgun service. Maybe drop them a note and see what they can do for your Ruger. Cheers.
My wife has a J frame 642 that was ported from the factory. The effects are noticeable especially with heavy bullet +P loads and makes it more comfortable for practice sessions with snappy loads.
Personally, I don't like ported barrels. I don't want the extra flash or noise pointed in my direction... They also don't help the value of the gun. I'd look into lighter loads and/or more comfortable grips or a gun with a different grip frame like the Bisley.
If you are sure it's what you want, Mag-na-port is known for quality work. You might check with Jack Huntington too.
I had a S&W 686 Plus (7 shot) .357, limited edition, factory magnaported with a 2 1/2" barrel. It was nice, but a snubby that big isn't that useful for me. I sold it to some dude I worked with that I didn't like for a little more than I paid for it.