[damien c]

Swap out the GTX770 for either a 4Gb 770 or a AMD R9 280X.

Games like Battlefield 4 are now starting fully use 2Gb of Vram so adding the extra 1Gb or 2Gb will help.

A SSD is a must these days when considering gaming since the maps are getting bigger and bigger.

Get the K version of the cpu as it won't be much more in cost but will give room to overclock in the future to, prolong the time between upgrades.

Swap the motherboard for something like the MSI M-ATX board.

Power supply is fine.

Cooler might be abit tall but I cannot remember fully what the height can be for the cooler.

As for the I7 Vs I5 bit, games will be coming out over the next 2 years that will use the hyperthreading available on the I7's, the I7 will give better performance in programs that can use it such as video editing and photo editing etc but, in most games at the moment there is no benefit.

If you want to prolong the upgrade time then grab the 4770K and possibly a Corsair H100i or H80i, and that will see you right for quite a while.