Everyone started some place and 38/357 is as good a place as any. In the last 45 years, I have owned between 95 and 105 S&W revolvers and currently have 16. 4" guns are a standard for holster carry since WWII, but 5" and longer were common before that. That may be a holdover from Black Powder days.
The most common S&W revolver has to be the Model 10, called a M&P before 1957 model numbers never existed. The stainless equivalent is the Model 64 (Not old enough to have a name). I have owned several 10's and one 64, and find them to be a tried and true standard for firearms! The 4" guns I had all shot about the same accuracy. I stumbled into a 6" model 10-7 as it was being traded in. It is the most accurate fixed sight gun I have ever owned. You might wish the "Lengthen your List" when finding used guns.
As to 357's; they started in N frames, which can be considered heavy for all day/everyday carry. So, S&W brought out K frame 357's as duty guns. They have a few minor problems as a group (but not many problems as individual shooters). SO, S&W brough out the 586/686 series (581/681 is the fixed sight version). N-frame upper half, K frame grip, weight about in the middle. I had One 4", a "No-dash" with the "M" (for factory recall service), my brother had a 586 6". We found nothing that outstanding about the guns and opted for 4" or 6" N frames.
3" N-frames are a niche gun all their own, and worth a long look at.
I would like to invite you to a different area of S&W revolvers: The big bores! From turn of the Twentieth Century 44 Specials, through the WWI 1917's in 45 ACP, the 1920's with Steer carved grips, the late 30's in 357's, The Military Targets in 44 Special & 45 Colt to the "Dirty Harry Days" of 44 Magnum. There is also the "Cult Following" of the models 57 & 58, in 41 mag.
The Wonderful World of N Frames! My personal shortest is a 629-10 with a 2 5/8" barrel to my longest, a 29-3 Classic with a 8 3/8" barrel. There are dozens of variants, and always something new on the Horizon! As both a warning and an encouragement remember: IT ONLY TAKE ONE TO BECOME HOOKED! My first was and is my 4" Model 28-2, in 357, I shoot it with a fairly heavy loaded 180 grain load I developed for a companion carbine. The heavy load has a felt recoil of a target load in a 4" model 10!
Yes, N frames will pull your pants down, if you let them! They will also cure whatever ails you, if you give them a chance.
In addition to your N frames, you also NEED a brace of 22's. A K-22 (model 17/617) with a 6" barrel is considered to be one of the finest revolvers on earth. A Kit Gun (J frame 22 with 3 or 4 inch barrel) is also a fine gun for anyone outdoors.
This is totally outside the area you were looking at, and uninvited, however I didn't want you to wander around for years without knowing the JOYS (and expense) of the world of N-Frames.
Ivan