Welcome Jonathan,, nice to have you with us on GTA.....
The fill adaptor for the Air Force rifles does indeed use a K valve setup.
The SS is a nice shooter, powerful, accurate and very quiet.
The Condor is also a fine shooter, however the emphasis with the Condor is power. If you need such power, or just want it, then the Condor is a good choice. For light woods/small game hunting the SS will work very well. Plus you'll enjoy the added benefit of being able to shoot it in residential areas, provided it's safe to do so of course, as opposed to a Condor which is not so "neighborhood friendly".
I currently have a .22 cal 18 inch barrel Talon (not the SS). I love the rifle and use it for small game hunting. It has plenty of power and is extremely accurate, however it is much louder than the SS, loud to the point where I cannot shoot it in my backyard like I do with all my springer rifles.
One thing to remember,,,,, you have a lot of options with the Air Force shooting system. Later on down the road if you want you can add a 24 inch barrel to that SS. A 12 inch barrel SS at max power will give you around 23 FPE, depending on the pellet. Add a 24 inch barrel to that SS and you can raise that FPE to the mid 40's. Of course the noise level will increase as well.
Whatever you choose I'm sure you and your son will have many hours of enjoyment of enjoyment with your new rifles. And remember,,, make sure to post your hunting stories and pics in the "Hunting Gate" for the rest of us to enjoy :)
Again, nice to have you with us......
Jeff