When I first became aware of the S2K, I put myself on the lists of several gun shops for a Glock 19 version. The lists were (probably still are) long. One shop in my area called the Kel-Tec distributor they used and he told them that "Kel-Tec doesn't make that model anymore". I spoke directly to Kel-Tec and they vehemently disagreed. The distributor in this area is (or was) an idiot.
I ended up buying the first Glock S2K that I came across. It is configured for G17 mags. The grip fits my hand, with all fingers around the grip. It is my understanding that the G19 grip on a S2K is short like a G26 with your little finger wrapping under the standard magazine floor plate. Now, with hindsight, I am glad that I purchased the G17 version. I think I would still be on those lists otherwise.