I think it's really hard to go wrong with a 642-1 or 442-1 for a pocket gun. However, I should add that I don't pocket carry because IWB works better for me, but with suitable clothing and a good pocket holster a snub can do a good job filling that role. Lightweight, compact, controllable with proper load selection, reliable, and easy to operate. There's no exposed hammer, so there's nothing to snag while drawing. They're double-action only (DAO), which is good for a self defense gun. Single-action capability in a defensive gun is over-valued, IMO, and not necessary. They're also not that expensive and are readily available, which helps.
At the same time, lightweight snubs are not for everyone. I'd suggest trying one out, either borrowing from a friend or a rental range, if possible before buying.
If you still want to go the lightweight snub route, I recommend the guns without the internal lock, so either the 642-1 or the 442-1. There are other options, such as the scandium framed guns, but I don't think the additional features they offer justify their increased price over the 642-1/442-1. YMMV.
Some people prefer the 442-1 because the finish holds up better than the clear coat on the 642-1, but the steel components are carbon steel and can rust if not cared for properly. I prefer the 642-1 because the stainless steel components don't require as much preventative maintenance, which can be a factor in hot, humid environments like FL.
Many people recommend against lightweight snubs as first guns, and for the most part it is better to start with heavier, larger revolvers, like K-frames, but not everybody has the means to do that. It does take some time to develop proficiency with lightweight snubs. Get some snap caps and do a lot of focused dry fire practice. Start off with light target loads until you're comfortable with them, then you can move up to more powerful loads if you want. When I started carrying my 642-1 I carried Federal 125gr Nyclad at first, but then transitioned to Speer 135gr SB-GDHP +P when I got used to shooting +P ammo. Of course, you don't have to move up to more powerful loads; there are a number of self-defense loads available for those who prefer loads with less recoil.
I think the disadvantages to .357 Magnum in a snub, particularly a lightweight snub, far outweigh any advantages. Yes, even in a short barrel the .357 Magnum will generate more power in terms of muzzle energy, but the cost is increased muzzle blast (and flash, with some loads), increased recoil, and increased shot-to-shot times. Some people like to say that in a real self defense situation you won't feel the recoil. To a certain extent that's likely true, however it doesn't change the laws of physics that say a gun with more recoil is going to have slower follow-up shots than a gun with less recoil, regardless of whether or not the shooter feels the recoil. Add to that the data that shows nearly all service caliber rounds, including .357 Magnum, perform about the same in actual shootings. I see no advantage to carrying .357 Magnum in a lightweight snub.
Just my opinion, FWIW.
