I'd say a 4in. barrel Ruger, S&W or Colt would be a safe buy, new or used. Depends on what you want to spend and/or new or used.
Have you shot a .357 magnum? They're very loud and pack some recoil. I wouldn't really recommend a lightweight for your first .357 Mag. Go with an all steel as the weight will help with the recoil. I know a lot of folks buy the .357 and only shoot 38 spl in them, but that defeats the whole purpose of the .357 mag round. I like to shoot 38spl's in 38spl's and .357 mag in .357 magnums.
The .357 is a great round and good for self defense, range time, and all around fun shooting, good luck with your choice.
NRA life member
When the going gets tough, I just open another beer.