Don't bother with a GPU if you're gonna go sub $600. You can have the CPU use its video support with high quality/capacity RAM and still get really good performance. Cuts out a chunk of the price unless you add that back up again with more expensive parts. And when he has the money he could get a GPU and get a big performance gain.
Also you're missing an optical drive there. Can't load that DISK OS without a DISK READER. (Unless you want to really take up more time and install it via USB, but there's a lot more you'd need an Optical Drive for than the OS)