Get the SP101 to go with the Security Six!
The trigger spring can be replaced in the SP101, which will help the single action pull a bunch,
Goes without sayin'.
My Security Six turned into a Blackhawk a long time ago. It was a nice gun, and I do not regret the trade, as I was cash limited in those days. The BH is easier to shoot well with. I bought the SP101 because I just liked it.
It is quite accurate, and would certainly be adequate enough for anything you might want to shoot with a .357, but really powerful loads with heavy bullets are not a lot of fun. It's much nicer in a holster than a BH. +/-/+/-?