I have a Model 60 and have shot a SP101. To be honest, if you plan to put a bunch of Magnum rounds through either one, you may want to consider adding some shooting gloves to your range kit. I have the 3-inch barrel on my Model 60 and with factory .357 Magnum rounds, the recoil is definitely noticeable. As I originally planned to carry the M60 with Magnum ammo, I wanted to be familiar with it, so I put a box of 50 rounds through it. Nothing fancy, just a box of Blazers, but the experience left a painful reminder that was with me for a few days while the hand muscles between the thumb and forefinger recovered. The revolver itself was quite happy and ready to go again.
After a bit of reappraisal, I decided good old .38 Specials were adequate for SD ranges.
In your case, if you really want to carry the Magnum rounds, I'd recommend the SP101 with a 3-inch barrel. Every bit of additional weight will work to your advantage.
Incidentally, you should also be aware the Magnum rounds are going to produce a lot of muzzle flash from either the 2-inch or 3-inch barrel.