I have an SP101 and love it. It's the DAO with the spur-less hammer and the 2 1/4 barrel. It's got enough mass to shoot comfortably with all but the heaviest loads. It's just the right size for me as a smaller carry. I shoot pretty tight groups with it too.
On the other hand, the LCR is very light and compact. It's easy to to carry and hide if you choose to CC. It's really a bit light for .357 loads but I don't think that'll matter much in a survival situation. Even with .38spl it's a little stiff to shoot, on par with a S&W airlight J-frame.
For their intended use, both are excellent choices. One thing you have going for you if you stay with Ruger is that their DA revolvers all work the same so there's less to learn when switching between them.
I really like Ruger revolvers and feel only Colts are superior. (I said FEEL all you flamers.) S&W makes excellent revolvers but feel and operate drastically different. I would recommend you go to a range that rents out fire arms and try out an LCR, an SP101, an airlight J-frame, a steel J-frame, and a K-frame.