Here's what I've got:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811815014 - Case
http://www.newegg.com/Product/Product.aspx?Item=N82E16814130828 - GPU
http://www.newegg.com/Product/Product.aspx?Item=N82E16817703034 - PSU
http://www.newegg.com/Product/Product.aspx?Item=N82E16820104387 - RAM
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157315 - Mobo
http://www.newegg.com/Product/Product.aspx?Item=N82E16835103099 - CPU Cooler
http://www.newegg.com/Product/Product.aspx?Item=N82E16819117286 - CPU
So that's $592.93, with $35 in rebates.
The main choices to look at are CPU and GPU. The CPU is a bit cheaper than a comparable i7, as this too is quad-core and is hyperthreaded. The comparable CPU is the
i7 3770. The GPU isn't super high end, but it should provide acceleration for the Adobe programs your brother in law will be using. It should also provide more than adequate performance for most games that you'd want to try out.
The case is good quality and has plenty of room, and should be large enough to accommodate the CPU cooler, and will keep the rest of the parts with plenty of circulating air.
The PSU is overkill a bit, but is of great quality and is modular (you can plug in the connections you need, rather than leaving a ton of extra cables hanging off that are unused).
The 8GB of RAM should be plenty for what is going on, or you could consider going 2x 8GB modules if desired.
It does not include any hard drives, as requested.
Hope this helps.