Gaming PC - need advice/mobo

I would consider switching to a 7200 rpm drive. The Samsung Spinpoint F3 or Seagate 7200.12 should be at a reasonable price, but it won't compete with that $40 for the 5400 rpm WD drive. It's not the end of the world if you get the 5400 rpm drive, but it is likely to be somewhat slower than the other drives mentioned.

If this ASRock Extreme3 870 mobo is available at ncix, it would be a good choice. USB 3 & SATA 6.0 Gb/s.

The GTX 460 is a good card, though if you want to upgrade, you'll need to put in a bigger/newer card, rather than going CrossFire/SLI. Assuming you're fine with that (and really, there's no reason not to be ok with that), then it's a fine card. If you want to CrossFire, I'd recommend a different mobo and going with a 5850 instead of the 460. But that might break your budget, so it's probably not the way to go.

Alright, I chose Seagate Barracuda 7200.12 hard drive instead.

That mobo wasn't available, but I did find this one, is it any good?
ASUS M4A785TD-V Evo 785G Socket AM3 DDR3 2PCI-E16 1PCI-E1 3PCI Video Sound GBLAN 1394 Motherboard

That one won't allow you to CF (the second PCI-E is x4), so you might as well spend an extra $2 and get SATA 3.0 and USB 3.0: http://ncix.com/products/index.php?sku=53570&vpn=M4A88T...

CASE-Lancool PC-K58B ATX Advanced-$49.99 CAD
http://ncix.com/products/index.php?sku=47120&vpn=PC%2DK...
http://www.newegg.ca/Product/Product.aspx?Item=N82E1681...

RAM-G.SKILL F3-12800CL8D-4GBRM Ripjaws PC3-12800 4GB 2X2GB DDR3-1600 CL8-8-8-24-$89.99
http://ncix.com/products/index.php?sku=42746&vpn=F3%2D1...

same kit as you picked but cheaper
CORSAIR XMS3 4GB CMX4GX3M2A1600C9-$87.99/$72.99 after mir
http://www.newegg.ca/Product/Product.aspx?Item=N82E1682...

Fast ram-Mushkin Enhanced Blackline 4GB 7-9-7-24-$91.99
http://www.newegg.ca/Product/Product.aspx?Item=N82E1682...

CPU-AMD Phenom II X4 955 -$147.92
http://www.bestdirect.ca/products/223993/AMD/HDZ955FBGM...

MOBO-Gigabyte 880GMA-UD2H - $99.50
http://www.swiftgamers.com/ProductDetails.asp?ProductCo...
GIGABYTE GA-880GA-UD3H -$111.91
http://www.bestdirect.ca/products/228695/Gigabyte/GA_88...

HDD-Seagate Barracuda 7200.12 1TB SATA2 -$59.99
http://www.ncix.com/products/index.php?sku=37232&promoi...
Seagate Barracuda 7200.12 500GB-$39.79
http://www.bestdirect.ca/products/208574/Seagate/ST3500...

OD-Samsung SH-S223C 22X DVD Writer SATA Black OEM -$16.99
http://ncix.com/products/index.php?sku=46792&vpn=SH%2DS...

Just some suggestions and as you already know pricematch.
Good deal till the 13th $5.99 shipping for whole order.