GSG is the way to go between the two. I've handled both and the GSG is nicer for sure. That said, don't forget the Colt/Walther:
Colt/Walther 1911 Gold Cup .22 LR Review | Modern Rifleman
It is very comparable to the GSG in terms of quality, but has a better finish.
The Colt/Walther is very competitively priced compared to the GSG. The prices go as so:
Govt. Model ~$350
Rail Gun ~$370
Gold Cup ~$400
I did a little better than that on my Gold Cup at Top Guns, but those tend to be the prices. The nice thing about the Colt/Walther is that the slide is aluminum rather than zinc alloy as is the case with the GSG.
Had a used Chiappa for about a month, decent quality but wouldn't function reliably at all. Buy a GSG or the Sig.
Actually the slide on the gsg is aluminum, the frame is zinc alloy.