I think you have the 649 and the LCRx reversed. At any rate I vote for the LCR since I'm looking for a good deal on one in .357 flavor myself.
Either one of the two will work, the weird thing is is about the plain jane LCR is actually heavier that the 3 inch model. I handled both the other day at my local gun store and the regular LCR is actually heavier, why Ruger did such an odd thing, I have no idea.