Here's my alternate build.
CPU:
i5-3470 You picked a great CPU for a gaming rig. Quad core, 3.2 Ghz. $199.00
CPU Cooler:
XIGMATEK Gaia 120mm I'm kind of a cooling Nazi, but every computer problem I've ever had has been related to overheating so I make sure things stay cold. You can probably get away with the stock cooler as Intel's aren't horrible (not like AMD's garbage) but... well it's $20 to make sure your CPU never cooks itself. $19.99
Mobo:
ASRock H77 Micro ATX You get 4 slots for RAM, a PCI Ex 3.0 slot, 2 USB 3.0 ports (on the back, yeah it's not perfect), 4 SATA 3 connectors, 4 SATA 2 Connectors, and it supports RAID set ups on board, and an eSATA connector for a very fast external hard drive. It's a very nice board. $89.99. There's a slightly less expensive option that has fewer SATA 3 connectors and no eSATA for $69.99 (regularly $79.99).
RAM:
G.SKill RipJaws 2x4GB That'll leave you two slots open. Corsair is good stuff but I've had this in my last two desktops and it is rock solid. It's also 1.5v right out of the box. I swear by this RAM. $49.99
GPU:
GIGABYTE Radeon HD 7850 2GB 256-bit GDDR5 PCI Express 3.0 x16 My opinion of NVidia has been in decline. I have yet to upgrade my drivers that my system didn't immediately shit the bed and require a roll back to an older set to keep working. NVidia has driver issues. Good hardware and the drivers usually get sorted out but the drivers are such a pain in the ass it's not even funny. So I'm committing the ultimate sin of an NVidia fan boy and recommending an AMD card. $184.99 and you get a free copy of Bioshock Infinite and Tomb Raider. Kind of a good deal if you care about those games.
Storage:
Crucial 256GB SATA 3 SSD Yeah, that SSD is kick ass enough that I'd go ahead and buy it right now. I'm trying to figure out how I could afford it myself. With the SATA 3 mobo you'll get the speed you expect out of it too. However I'd also add in a regular drive. If you current one is iffy replace it.
Seagate Barracuda 1TB 7,200 rpm Again, this is my default drive. It's technically a SATA 3 drive but conventional hard disk technology isn't likely to make any use of that unless it's got what you're going to ask for cached. $159.99 + $79.99
Case:
COOLER MASTER HAF 912 It's going to be bigger than an ITx case but it's a mid tower so it's not a monolith either. The benefits you get are much, much better airflow and less concerns about the size of your video card. It's also a Cooler Master and it's got a bottom mounted PSU instead of a top mount. It comes with a pair of fans installed with space for several more 120mm fans if you're a spaz like me. $59.99
PSU:
CORSAIR CX430M 430W BRONZE Certified Modular It's $3 more than the standard 430 but for that you get modular cables so you only use what you need and don't clutter up the case with lots of extras. $49.99
Odds and Ends:
COOLER MASTER 120mm Case Fan 4 in 1 pack Enough fans to fill the extra openings in your case with some left over. You don't need 4 but then this is a hell of a deal. You can pay more and get some LED fans that's up to you. $11.99
SATA 3 Cables You want two, and use the ones that come with the board for your DVD-ROM and old hard drive. $8.58
$915.48 and with a copy of Windows 7 the grand total is $1,006.65. So forget I mentioned the extra fans.
So what do you get?
CPU: Same but with a cooler.
Mobo: SATA 3 Support, 2 more RAM slots, a PCI Express 3.0 Slot
RAM: 1.5V out of the gate
GPU: Double the VRAM
Storage: 1TB conventional Drive
Case: Better airflow, no space worries
PSU: You get one, and it's modular
So yes, you're paying a premium over what you've got listed but you still need a PSU for your build, you'll have no SATA 3 support so your SSD is hobbled, your GPU is hobbled by an older slot style, and I think cooling is going to be a real problem on more advanced games.
Oh, but I should mention this is not a set up designed for overclocking. The CPU and Mobo would need to be changed out. You'll have plenty of cooling but if you wanted to overclock this is not the set up for it. On the upside, there's not much point to overclocking. This thing will run every game that comes out for the next two years on high settings. I built my last PC on pretty much the same concept and I still hit over 50 FPS even with things maxed out on any game I've put on it. When it comes time to upgrade you'll have a PCIE 3.0 slot so with 8 more gigs of RAM and a new video card you'll be good for two more years for maybe $250.