Well, right out the gates, a .32 Mag is going to limit you to field pistol silhouette categories. Either the .41 mag or the .45 Colt will do fine in the big bore catergories. Now as far as shooitng 150-200 rounds into one ragged hole, I can't think of anyone who wouldn't want that. However, wanting and doing are two entirely different matters.
Now, if you are serious about shooting silhouettes with a FA revolver I recommend you look at the Model 83 instead. There are silhouette models of this revolver. Also, the Model 83 is a heavier firearm and you will not be as fatigued from recoil after a 40 or 80 shot relay.