Oops. For some reason, I thought it was just $10 more than the 509 display unit. Don't tell my second grade teacher.

Once you found an OEM remote for that display unit, though, it would probably be darn close.
The 313 looks like it has everything that you stated wanting...but if you haven't, I encourage you to check out the handy comparison chart of the models on Amazon. Just scroll down the page for either the
313 or
414. What you give up going from the 414 to the 313 includes cloud streaming, internet radio, and an iPhone remote application (among other things). I mention those three because your son might want those.
Neither the 313 or 414 have room calibration. For me, that is a really nice feature to have, but you'd have to go to the 515 (in this year's line) to get it.
If this isn't a suprise gift, you could always ask him if there's anything that he'd really miss between the two. Of course, if he's like I was at that age, he'll find some case for the 414...and then the 515...and then...