OP, have you actually tried the trigger on the SP2022? Don't want to discourage you but if your son is okay with it, that's fine, get it. However, I was considering one but passed on it because the trigger, IMHO, was not up to par with what I would expect from Sig. I found the trigger to be long and mushy. Maybe that can be remedied and maybe it was just on the pistol I was holding but you should be aware of it. I am not a Sig basher, they make fine firearms but I would encourage you to compare it with other handguns.
I know I’ll probably get a lot of flak from the Taurus bashers but if price is a concern, my suggestion is a PT809 (9mm) or a PT840 (40 S&W). I have the PT840 and it has been very reliable, as accurate as I can be with a pretty darn good trigger. It is also hammer fired (my choice in handguns), double/single action and a breeze to maintain and disassemble. It may be $50 to $75 cheaper than the SP2022. If you can do a side by side comparison you will know what I’m talking about.
There may be others to consider but this, so far, is my experience.
Another one to consider, in the price range, would be the EAA Witness. Its hammer fired and comes in 9mm, 40 S&W, 10mm and 45ACP. I once owned the 40 S&W version but traded it because I thought I would like something else. hwell: It had a good trigger and the pistol never gave me a bit of trouble.