.357 Sig is a rather nasty caliber to shoot. It kicks and all the ones I have fired suffer from excessive muzzle jump.
It is not a caliber you want to shoot a couple of hundred rounds of at a time.
If you want a power trip, get a .44 Rem Mag or even just a plain old .357
Actually, my .357 is nastier than my .44 probably due to the weight of the guns.
A consideration is the price of .357 Sig ammo (expensive); or if you reload the scarcity of .357 Sig brass as well as its shorter life before failure. It is a high pressure load and the cases will split sooner than say .40S&W;
But if your heart is set on that caliber, then go for it!