There really isn't any "Best" model. There are those that more desirable, more expensive, somewhat better estectis, some easier to find and therefore cheaper.... much depends upon what your needs are.
I have a couple of 48's from the later 1950's and early 1960's, but rarely shoot them. I find little to justify the additional expense of the .22 Magnum round. Mine are collectables.
If you want to shoot a K-22 maybe you should consider a .22 Long Rifle Model 17 instead. That havng been said, 48's from all eras can be good guns.