I have both the S&W 642 Airweight and a Ruger SP101 .357
The Smith is a really light gun. For me, it's a close range gun compared to my Glock30 or 1911 which I can shoot at longer distances accurately.
I prefer to carry the G30 'cause it's .45, but I don't feel undergunned with the .38 +P loads in my Smith.
I went through various grips and settled on the Crimson Trace rubber grips. They feel good in my hands and I have the assistance of a laser.
I practice with the laser and without it. It's an accessory not a primary aiming device.
I've carried it in my pocket with an Uncle Mike's pocket holster, belt carry with either a Don Hume JIT, GALCO Slide Master, GALCO Summer 'something' IWB, a bellyband (not too fond of that one), Uncle Mike ankle holster, and my ALL TIME FAVORITE...Ken Null SKR (shoulder rig).
It has carried well with all of these holsters. I actually only use four of the methods above...SKR, UM ankle (I'm going to get a real nice ankle holster one of these days), either GALCO belt holster and the pocket holster.
I have a redgun S&W J-fram model, which I modified to take factory grips so I can practice without the real gun, and I also practice with the actual gun itself.
Someday if my wife ever comes around to the idea of getting serious about handguns for protection I'll pass this one along to her...but I'll hate doing it!
The SP101 is bigger and heavier, but packs a wallop! I have the shorter barrel and kinda wish I had gotten the 3" or so barrel.
I have used it for a field gun carried in a Bianchi Accumold holster.
I tried several grips and finally stayed with either the Butler Creek (?) or the Pachmeyer, I don't remember right now which ones.
For speedloaders, I use SL Variant (which are hard to come by in the states now), and Jetloaders.
The Jetloaders fit the Smith really well, while either one works for the Ruger.
If I want to carry even more ammo but with less bulk, I use the Bianchi speedstrips.
Pretty longwinded...but that's just how I am...Sorry!
Hope this helps.
btw, I'm 6'2" and about 210lbs with fairly big hands so the Smith is a bit small but a sure enough fit and the Ruger is just fine.