the i5 2500K is a great OC (less heat due to no hyper threading). If you are not OCing then get the non-K version and save a few bucks. An aftermarket cooler is not really necessary unless you are 1) doing a major OC (more than 300MHz), or 2) you want something quieter than the stock fan (or want something ugly and flashey). The hyper 212 is a great cooler that I plan on getting down the line to replace my Zalman. It is cheap, quiet, and works as well as entry level water cooling solutions. It's not as pretty as an all copper zalman, but really looks dont matter that much so long as things are simple, clean, and quiet.
HDDs are super expensive, but as others have said, the prices will slowly go back down over the next 6-8 months. 2TB is a HUGE amount of space. I do video editing, in HD, and 2 1TB is more than enough space for even large projects (camera shoots in AVCHD). If you are editing in an uncompressed format then 2TB will not be nearly enough... but nobody does that anymore. Now, 2TB may not be large enough to do a large movie collection, but that project can wait for a bit and save a lot of money. Also Hatachi Deskstars have improved over the old IBM "Deathstars", but I would still go with a different brand. Look into Samsung F series, or Seagate (I love Seagate, and have a 6 year old 1TB drive which is still running strong. But read reviews as they have had a few flop products over the years).
Why the 2GB version of the 560? 1GB is plenty for video games unless you are doing over 1080p, and multi-monitor setups, in both cases you would want something more than a 560 anyways. You dont even need the 2TB version for video editing. Also, the new 560ti that is coming out 'before christmas' is supposedly going to be as fast as the 570, which is worth considering (I love my 570 OC
). The only other reason to get the 2GB version would be to do some big Maya or other 3D content creation projects, but even then we are talking about a situation where you should really be buying a Quadro card anyways.
Lastly, 700W is way overkill for that setup, and barely enough for SLi. If doing a single card setup then 600-650W is plenty, even if OCing. If doing a duel card setup I would suggest getting a 750W to be on the safe side.
Even without my advice it looks like a fun solid rig! I hope you enjoy it!