What I'd definitely change:
Microsoft Windows 7 Home Premium Upgrade is just that, an upgrade. As in if you do not have a previous Windows installed, it will not update. Think of trying to run an expansion pack without having the core game installed. What you need is the
OEM edition (don't worry its cheaper). Its on sale no too, and yes you want the
64-bit version. If your brother has a Windows Vista or XP OEM CD lying around than this isn't a problem, if not then this is mandatory.
What I'd might change:
That ASRock motherboard seems a bit overkill. Maybe you should look at
ASUS's lineup (the parent company as well as the "official brand".
Intel is by far the most reliable SSD manufacturer. And SSD in a high-end computer today is mandatory. Its half the "next-generation experience". That being said if you want to pony up an extra hundred dollars you can grab a SSD big enough to put some of your games on on Steam or similar services. You will be shocked at how significant load times are cut at times. Just something to think about.
Other than that everything looks great! Great job!