I've been reading Tonymac for quite a while, and have chosen highly compatible parts - there are several Hackintoshes VERY closely related to what I'm doing that are already running very well. This is going to be a powerful machine, easily equivalent to a midrange 2013 Mac Pro (if such a thing were to exist), and faster than any present Mac Pro except for the fastest version of the 12-core. The final decision is whether to throw in a $100 graphics card (it has no motherboard graphics, because it's an X79/ i3930k 6-core), or install a powerful card - obviously, I wouldn't skimp on the GPU in a machine of this price and power if there was a real benefit to be had by going higher-end, but I'm not sure that there is any real benefit for a pure photo/video machine (I am a landscape photographer and photography professor, and I may very well start doing some video work - I've had some ideas about the moving image in the landscape - but I have no interest in gaming beyond the occasional round of Angry Birds while riding the bus to work, and I can't see myself doing 3D or CAD, either).
In case anybody's interested, I've posted a description of the proposed machine below (all parts from Tonymac, and there are machines configured almost exactly this way in highly successful builds - one of them is what they call a Golden Build, which is the most stable group of computers people have put together). This will run Mountain Lion (either 10.8.3 or 10.8.4 if that's out by the time this sees the light of day).
CPU: Intel 3930k. To go any faster than this $600 CPU requires either a $1000 chip (and it's only 5% faster) or dual $1500+ chips for a speedup of only 15-20%. It's just not worth it. On the other hand, photographic applications DO tend to be multithreaded, and this 6-core CPU is quite a bit faster than the i7-3770 in the fastest iMac (plus these 6 core Socket 2011 parts support 64 GB of RAM). I'll overclock the CPU modestly (I'm thinking 4.2 gHz, which is easy on this chip and motherboard, and still runs cool and relatively energy-efficiently), while emphasizing stability over a huge overclock.
Motherboard: Asus Rampage IV Extreme. This has a reputation as the most stable Socket 2011 board around,largely due to extremely high quality power regulation. Some Socket 2011 boards, including the Gigabyte that is the other popular board on Tonymac, have 8 RAM slots, but aren't always totally stable with RAM in all 8 slots - this one will run all day with 64 GB!
RAM: Either 32 or 64 GB of DDR3 1600 mHz RAM. I would start with 32 GB, then go to 64 only if necessary, except that there are several articles saying that the most stable way to get to 64 GB is with all the RAM purchased in a single set of 8 DIMMs, and I'd hate to throw out 32 GB of perfectly good RAM in a year or two...
CPU cooling: Closed-loop water cooling (probably a Corsair H100i, or maybe a Swiftech). A nice compromise between noisy air cooling and the complexity of open loop water...
Case: Fractal Design Define XL R2 - look at the disk configuration, and that's why the big case with a million drive bays...
Power Supply: Seasonic Platinum (final wattage to be determined once the graphics card is chosen). The Seasonic Platinum series are the best, most stable, most efficient power supplies on the consumer market. To do better would mean a MUCH more expensive server or lab instrument power supply.
Boot disk: Samsung 840 Pro SSD (512 GB). Fast and reliable. There will also be a boot disk clone on a commodity hard disk, just in case some update messes the system up - important on any machine, but especially a Hackintosh...
Primary storage: 8 Western Digital Caviar Red 3 TB drives in RAID 6, driven off a RocketRAID 2720SGL. About 16 terabytes of usable space after formatting and RAID! Not cheap, but a lot less expensive than this kind of storage would have been until recently.
All in all, this aims to be the Mac Pro Apple should be making - fast, reliable and capacious storage... They used to make 'em like this, but then started getting so obsessed with iToys that they forgot to make Macs for the people who kept them going in their darkest days - photographers and filmmakers who stayed loyal to the Mac when EVERYONE used PCs...
-Dan