If you have shot the 50 AE you could always start with a SW 500 and work your way down. That is an awesome revolver and it sounds like you are up to the recoil. Of course you have to shell out a cool $1K to start plus ammo at $3.00 a pop
Personally if you are not buying to carry but for fun.. get the .44 magnum. They are a blast to shoot as well. As for the .357's. I would go with the lighter K frames. They are also a blast because you get more bang with the lower weight frame, it is easier to conceal and that myth about not handling .357's is truly a myth. If you don't use the hot 125g loads you can't find enough time or ammo to wear one out. IMO Or go with the Ruger... but keep it light weight.