If you aren't planning on carrying concealed, and if you want a .357 revolver, I am a bit puzzled as to why you would opt for the SP101, especially in 4.2" configuration.
Five shots vs six or seven in K or L frame sizes, or eight shots in N frame; lighter weight is great for carry, but at the range or used in home defense only equals greater recoil.
So, if I were looking at a range/HD .357 revolver, and I had medium hands as the OP claims to have, I wouldn't look at an SP101, or a J-frame, or an LCR. I also wouldn't look at an N-frame.
I would look very hard at a Ruger GP100, or used Security Six, Service Six, or Speed Six. I would look very hard at a S&W 686, or a used model 13, 65, 19, 66, or 586.
I would also look at a 3" or 4" barrel. For the range, a 6" might be nice. For HD, the longer barrel provides a bad guy with more leverage for a takeaway.
My own .357 revolvers are a Model 13 and a Model 65, both in 3" configuration. Well, technically, the 65 is my wife's.