* CPU is fine for gaming.
* RAM, make sure you use LOW PROFILE heat spreader set and 1600 mHz at 1.5v in a set of 2 x 4 gb.
* CPU HSF isn't needed right away, but I'd opt for the CM Hyper 212 EVO over teh Freezer 7 Pro.
* Mobo will work just fine. Even the AsRock z77 Pro3 will do fine and might free up some $ for other upgrades.
* GPU should be fine, but I'd opt for a 7870 or 7870 XT LE Tahiti core, if it fits the budget.
* Case could use a bit of an upgrade. The Corsair 200R, NZXT Source 210 Elite, NZXT Tempest 210, Rosewill Redbone U3 would be some other options.
* PSU will work fine with any GPU needing only 1 x PCI-e power connector (up to GTX 660). Any GPU requiring 2 x PCI-e power connectors would require at least a 500w quality PSU.