Bigb ,both those rifles will last a lifetime and im sure you will make the right decision.I would like to give you something else to think about though.
I wouldnt buy a 9 yr old a expensive new rifle.I would buy myself a new bolt action 7mm/08 or .308.Both these cals are fairley lite kickers and are excellent deer medicine ,esp the 7/08.You can loan him the rifle every year but it will still belong to you.Tell him you will buy him a new rifle for his hs graduation.By then he will be 18 and have a idea what calibers and actions he likes.
This May I presented my son w a brand new Tikka stainless synthetic .308 bolt action w all the trimmings at his graduation party.He was nearly bought to tears. For the last ten years he had used my 7mm/08 mod 700 mtn version .i think he was more diligent in its care knowing it was my gun.
Like i said,just giving you another option that worked for me.BTW,Thanks for introducing him to the shooting sports.You are doing him a huge favor.DB