Build for Audio/Video encoding / gaming

All,

This will be my 4th build, but my first truly high-end powerhouse. Budget is somewhere in the neighborhood of $2,500 and the main reason for the build is Video editing with sound recording, etc. Some gaming of course, with Crysis being the game of choice (this is all for my nephew - not for me).

Case - Coolermaster Storm Stryker - looks just plain awesome to me
CPU - struggling here - Am willing to go with 3930K - but why not a newer Ivy Bridge? Video software does make excellent use of the multiple cores so am leaning towards the expensive 3930K.

MOBO - ASUS - P9X79 Pro - of course dependent on CPU above
or maybe - Gigabyte - Z77X-UP5 TH - if going with LGA1155 socket

Graphics - massive confusion here as some say a single powerful GPU is betterr than an SLI or Crossfire config with cheaper cards partly due to the complexity of chaining cards together. Will SLI or Crossfire help video encoding - or is that more of an intense gaming thing?

Memory - looking for fast memory of course - but 32 gig will be the order of the day to start with.

Drive Storage - Samsung 840 256 GB SSD plus additional TB drive of some sort (partial to WD Black)

Power supply - I prefer modular ones, but with a full tower has anyone experienced cable length issues reaching from bottom mounted PS to whereever? 80 Plus certified bronze at a minumum - enough power to drive 2 gaming class graphics cards - eventually.

An odd requirement is an IDE adapter or something to build XBOX drives - should just need a standard PCI slot for this

Any comments - all are welcome - a little bit of future proofing - but really want something that will perform for 5 years or so.

Finally - a side question on OC'ing - I never seem to read anything on how much faster OC'ing your components burns them out any quicker than normal use. If anyone has comments on this I look forward to hearing them.

Thanks