Oh man i am so in favor of building a computer that can run Crysis 3 and blender at the same time... that said, pretty sure programs are being run one at a time.
The parts list looks really good, should be a really nice computer.
The "silicon lottery" is just a term for how well a chip will clock. If all chips will clock at least X over stock, some chips will just have everything line up that little bit better and overclock an extra Y. For example, most 2500Ks can reach 4GHZ, but only a few will be able to reach 5GHZ. Overclock-able chips will still overclock, its just a question of how far and how close to the edge you are willing to push the chip. Im still running stock on my i5 because i dont feel a need to overclock just now. your 2600K should be even better, so i wouldnt upgrade. The temptation for shiny new things is strong tho. Either way im sure you will be happy with your rig
As for the RAM, anything over 1000 would be good. pick a reliable brand name (G.Skill, Kingston, etc.) and you wont go wrong. Look for whatever fits your colour scheme and if its on sale, all the better.
I agree, pick up a new, fast hard drive. Id use the Samsung in an external enclosure for movies or backups or whatever else.
EDIT: id get the GTX 780. If you decide to upgrade to one of the 1440p screens the extra grunt will be appreciated, and even at 1080p it will let the card run cooler and quieter.Edited by M3nta1 - 6/5/13 at 7:04pm