If you want a gun that will take your son for a long time and not need anything more than a rinse off and a few drops of oil, then it is the Blazer all the way. About the only mechanical gun on the market I can think of, next to an RT MAg, that keeps the electro carrying players really on their toes when they find out who is using the marker. Personally, when I get together to play, I like to keep the guys with the Blazers on my side, because they are dang accurate. That being said the Blazer is Palmers production gun, but they will customize it to your hearts content, there are many options available to choose from.
I myself, I do have a cocker, but I also have a Palmer Typhoon (unless you got some spare money to spend do not worry about these, the predeccesor to the Blazer is what it is) With the cocker, sure you got your choice of whatever aftermarket parts you want for it, I like mine, and it works great, and working on cocker isn't too hard if you know how to read directions. With my Palmer semi though, as with the Blazer it basically already has the best parts on it with no need or want to upgrade.
So myself it comes down to do I want to tinker with it and put different aftermarket parts on it or do I want a gun that will live up to my expectation just by opening the box and using it as it came.
If you go the cocker route though, an upper end used model is definitely the way to go now a days. It is a buyers market right now for those interested in a cocker.
I hope you find this informative, if I seem a little biased, sorry for that, I just love my Palmer products, but my Cocker is still great too. Good luck in your search.
Ready to form Voltron!! Activate interlock, dynotherms connected, infracells up, mega thrusters are go!! Lets go Voltron Force!!