because of your budget you cant really do very much for gaming. however it depends on what games you want to play. your budget and specs mean you should probably get the i5 (sandy bridge if you want to save on cash but lose some performance) and a cheap but good quality graphics card like the amd 6670. as for the mobo you should look around but make sure it has 1155 socket and a pci slot for the graphics card, also make sure it has enough slots for your desired ram. 4GB Ram should be enough but you can expand to 8 if you want. Corasir is a good brand for that. cases and psu are easy to find.