Ooo I'm going for the Core i5-3570 myself, I think someone mentioned the K can be overclocked but I don't know if there is any other difference. Seems to fit the socket and motherboard.
I've also bought that same hard drive, haven't tested it yet but looks good too. Some said it could get a bit noisy, others say it runs quiet. Strange.
The optical drive apparently burns at 2.4x after a little Google. If that is a concern for you, might want to rethink it. But if you don't tend to burn discs probably not an issue.
RAM looks compatible. Graphics card should fit into that one PCIe x16 slot on the mobo so that seems fine.
PSU is of a good brand, can't comment on what wattage you'll need but I imagine 650 is suitable. Might want to double check. I also noticed some people are saying it doesn't come with a power cord so you'd need to reuse, find, or buy one. The reviews are mixed on this PSU, some say its great but an alarming bunch of people warn of "burning smells". I recommend looking around for another.
If it was me I'd probably push up the RAM a bit more (maybe 2x8GB) and look for a new PSU, and maybe consider a better optical. But it seems like everything should fit together nicely, I'd probably go ahead with it. Might want to wait for a second opinion as I'm still learning all the terminology and what to look out for in individual components.
