Congrats!
We have a pre-17 five screw. It's the single most accurate handgun we own. For a K frame I'll echo the Magnas for a grip. These are open on the front and back strap and generally fit my medium large hand pretty well as opposed to the target styles grips on yours. On a round butt I find a grip adaptor very nice with magnas, but can take or leave the adaptor on a square butt. For comparison, here's a pic of magna's on our K-22:
On the 4" S&W .22's I'm not sure they're rare but they do tend to be pricy. Here's a GunBroker search for them:
https://www.gunbroker.com/Revolvers/...ength=4%20inch
Hope you have fun with yours. Should be a great buy!