I toss in my $0.02.
I've owned, shot and worked on a pile of revolvers; including some big bores. Over the years the 40 caliber + ones left one by one and the .357 caliber ones accumulated. I'm currently looking for a .44 but not as a replacement, only an addition. In todays world a cartridge that consumes less lead and powder each time it's fired has some real merit of economy over the ones that throw those big bullets. Don't get me wrong, big bullets have their place but the 38 Special/.357 magnum has a LOT going for it. Fun, cheap, accurate, versatile, reasonably powerful ...did I mention fun?
As for .357 caliber revolvers, we have some excellent examples to choose from. The Colt's are nice but almost in collector's only status and very expensive. The Smith v. Ruger thing is a lot like the Ford v. Chevy thing but I'll make some distinctions.
First let me say that I think the single action revolver is a fine design but it's not my choice for a revolver that may be called upon for more than hunting or target work. Ruger makes some outstanding single actions and I've owned some; but I prefer double actions for revolvers.
The excellent engineering and high strength of a Ruger GP-100 is undeniable. They are also far more accurate than most people will admit. I'm tried of hearing about the allegedly poor triggers on the GP-100. The trigger pull on a new S&W, "aint' all that" and the GP double action pull can easily be made to rival the current out of the box S&W. Don't over look the old Security-Six models or the SP-101's, they have some strong points as well.
The Rugers are strong, durable, accurate revolvers with outstanding engineering.
The S&W's have another forte - a very long design history and a LOT of variations.
With the S&W make you get multiple frame sizes, sights, finishes, steel or alloy frames, etc.
The S&W L-frames are plenty strong for anything one would want to do with a .357 magnum. The K-frames are works of art that balance size and power.
For a medium sized .357 revolver it comes down to a L-frame S&W or a Ruger GP-100. They are both excellent guns. The S&W has a few more variants and the GP-100 has superior strength and engineering.
If I had to have only one my choice would be the GP-100.
As for lever action rifles chambered in .357 magnum; your choices are a bit limited. The good news is most of what's available is pretty good. I owned a Rossi lever action chambered in 38/.357 that, despite it's low price, was actually not bad. It wasn't nearly the same quality as the American makes but it was surprisingly functional and accurate. I think when you start talking about rifles chambered in pistol calibers, the playing field is fairly level.