First gaming PC build.

Hey it's my first time really getting down and building a PC from parts, and figured here would be a good place to start. Im using PCpartpicker.com and this is what I have so far, just want someone elses opinion before byu it. Would set up be good for gaming? $900 is my limit, I don't need a monitor, or keyboard.

CPU: http://pcpartpicker.com/part/amd-cpu-hdz970fbgmbox
Cooler: http://pcpartpicker.com/part/cooler-master-cpu-cooler-r...
Motherboard: http://pcpartpicker.com/part/asrock-motherboard-990fxex...
Memory: http://pcpartpicker.com/part/gskill-memory-f312800cl8d8...
Storage: http://pcpartpicker.com/part/hitachi-internal-hard-driv...
Video Card: http://pcpartpicker.com/part/gigabyte-video-card-gvr787...
Sound Card: http://pcpartpicker.com/part/asus-sound-card-xonardg
Wired Network Adapter: http://pcpartpicker.com/part/rosewill-wired-network-car...
Case: http://pcpartpicker.com/part/raidmax-case-atx238wrp
(Didn't think I'd need a power supply, since that case comes with 450W, I fyou think I should get one, any Suggestions?)
Optical Drive: http://pcpartpicker.com/part/asus-optical-drive-drw24b1...
Operating System: http://pcpartpicker.com/part/microsoft-os-885370414059 (Now I know Windows 8 isn't that great, but I want to at least give it a shot. Can't judge it until I actually have time to inspect it.)
Mouse: http://pcpartpicker.com/part/kingwin-mouse-kw02

I am planning on gaming on this PC, and if you have suggestions on a different component that I should use. Like I said, $900 strict limit.