I don't see how the quad isn't much better for gaming. The total Ghz amount is quite a bit higher, and games will start being designed for them in the near future, so it's more future proof.
To save money:
PSU:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817339001&Tpk=hec+orion
Case:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119068
To save money:
PSU:
http://www.newegg.com/Product/Product.aspx?Item=N82E16817339001&Tpk=hec+orion
Case:
http://www.newegg.com/Product/Product.aspx?Item=N82E16811119068