Maximum PC

This is my first build that I have been looking at doing. I have done a lot of research but of course doing building something like this and investing that much time and money into it I figured that it would be really smart to ask the people that really know what they are doing. I listed the parts and the links below.
Case: Rosewill Thor V2 http://www.rosewill.com/products/1798/P ... erview.htm
mobo: MSI Z68A-GD55 (G3) LGA 1155
http://www.msi.com/product/mb/Z68A-GD55 ... v=Overview
cpu: Intel® Core™ i5-2500K Processor
http://ark.Intel.com/products/52210/Int ... o-3_70-GHz)
Graphics Card: Sapphire Radeon HD 6870 (100314-3L) 1024MB PCIe x16 Gen 2.1
http://shop.amd.com/us/All/Detail/Graph ... 90#Details
Hard Drive: Western Digital 1 TB Caviar Blue SATA III 7200 RPM 32 MB Cache
I don't have a link for this, really looking for some input with this. I really want to go cheaper than a hundred dollars on a good hard drive. Don't really need a ton of space, at least 500GB up to 1TB. Just wasn't sure how well this one would work.
Power supply: I am totally lost on this too. I used a power supply calculator from asus but didn't trust it too much. I figure that I need 1000W minimum to run everything, but not sure how much really and even what brand was good.
I have not decided for sure on the specific RAM yet but it looks like I would be going to at least 8GB dual channel DDR3 1333Hz ram from Corsair to start with because that was the highest amount commonly supported by all the components.
And eventually I also plan on getting another matching graphics card because the mobo supports AMD Crossfire, so I could get improved graphics.
I also plan on overclocking.
Any help with this would be greatly appreciated. Thanks.