I would go with something similar to this. Current generation Intel quad core (i7-4770), 16GB of memory, 3TB hard drive, middle of the road current generation AMD graphics card (R9 270X), Antec case with 500 watt power supply.
http://www.newegg.com/Product/Product.aspx?Item=N82E16811129024
http://www.newegg.com/Product/Product.aspx?Item=N82E16813130699
http://www.newegg.com/Product/Product.aspx?Item=N82E16819116900
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125476
http://www.newegg.com/Product/Product.aspx?Item=N82E16820148466
http://www.newegg.com/Product/Product.aspx?Item=N82E16822148907
http://www.newegg.com/Product/Product.aspx?Item=N82E16827136259
Could swap out the AMD graphics for Nvidia graphics if you want to do something with CUDA down the road. Could also swap out the hard drive for a SSD and smaller hard drive but I would just skip the SSD based on the budget.



