I haven't played with the airsofts,so I can't help there, but as to what steve said about the BB gun without the front sight, after some practice you would be surprised what you can do with it.
My son was around seven when I started him playing with one, I had to cock it for him at first, anyway the jist of the story is he's now 35 and I'm 63, and were still shooting buddies, actually we have a very close relationship, he's not only my Son he's my best buddy also, and I attribute alot of that to the time we spent target shooting and plinking, among other things. Good luck to you and your Sons, I think you are walking down the right road.............steg