If you are planning to upgrade things, get an fx-6300 and the best GPU you can afford. An hd7770 is going to AT BEST play modern games at medium at 1080p. You REALLY want at least a 7850 for a gaming computer.
The i3 is fine, but any games that use more than 2 CPU cores will struggle. BF4 for example will be rough. I previously had an i3 and it easily played any game but as soon as a game was clearly coded for 4 cores, it became almost unplayable.