I think with hindsight, and if I hadn't been having issues with tennis elbow in my right arm, I would probably have opted for the Gamo too. It has a more ergonomic grip than the HW40 so a bit more target oriented. The HW40 is ambi so I was able to shoot left handed for a few months til my right arm was ok again. The grip was the only thing I would've changed, and I didnt want to start sticking putty to the HW40 as it would've made a mess of it before I sold it on.
Depending what you really want to do with the pistol dont discount the crosman. The fact its CO2 means no cocking between shots other than pulling the bolt back. That's seems like a lot less effort than the Gamo or HW. Just the capsules you'll need figure in to your costs. I've only shot the CP88 and M92 CO2 pistols, lots of fun for plinking but after a certain number of shots you'll find point of impact starts to drop. So you'd need to change capsules or alter point of aim.