Going with the 357 over the 38 you get the same size gun to gain the option of being able to use two different cartridges. The power gain difference is a lot less than the cost you'll pay in recoil, but the option is there!
I keep Remington 158 grn LSWHP's in my S&W 360sc.
I can shoot full house 357 loads in the SP101 without discomfort.
I'd forget the porting.