If you must buy a PC, for god's sake don't buy that. Why not just build your own? PC's are completley modular, building one is like putting together legos.
It takes, at most, a few hours to build everything and have Windows/Linux installed, with all of your drivers. It is much cheaper to build your own, giving you equivalent power for less money, and much more power for the same amount of money. I would highly advise building your own.
If your not going to build one, which I highly recommend, I would recommend buying a pc from cyberpowerpc or ibuypower. They seem to be a little bit more reasonable. You could get this http://www.cyberpowerpc.com/system/CyberPower_Z77_Configurator/ but change the 650 to a 7770.