Here is something at the upper end of your budget. The case I picked was just a price holder if you will. Case choice is highly personal so feel free to shop around.http://pcpartpicker.com/p/22woo
using a 4gb 770, again only useful if you are using sli (which would require a more expensive psu) would put you at around 1200.00.
If all you want to do is gaming, I'd say get an i5 instead of an i7 (you won't notice a difference in games anyway) and get 12-16gb of ram, or a 780.