Re: Rifle for my son.
The .243 is a pretty good initial choice. So is the Rem 700. When he gets bigger you can swap the stock out on it for a full size one.
That said, anything in that same class is going to work for him, i.e. .250 Sav, .257 Rob, .260, 7mm-08. Although, the first two are hard to find in the Rem 700. The latter two are hard to find as long range platforms. But, you can deal with that when the time comes. That is, if he ever gets to where he likes that.
Savage is also a great buy for less money generally than the Rem 700. Right now, I would say that they are the best off the shelf rifle as far as accuracy is concerned. Remington has made an effort to get back on track in that regard though. A lot of aftermarket stocks are coming out for the Savages too. Not quite as good an aftermarket selection, but certainly adequate. Keep in mind Stevens is the same as the standard Savage. Except, they have some odd twists in their barrels. My 7mm-08 donor action had a 1-11.25" twist. It needs a 1-9.25 like the standard.
Howa, Tikka and CZ are some other brands I would take a look at.
Anyhow, there is a bunch of workable choices out there and you've hit upon the simplest, and possibly the best solution for your dilemma.