agreed with izam, you need to define those stated parameters.
also to add to izams list, do you do multicam editing?
There are some things I would change out from experience on Putuser's list,
1.dont go with the 3960x, the increase in over all performance is not worth almost double price for the 3930k, go with a 3930k it will serve you well. I have it and run cc for video and photo. it eats everything i throw at it with out even breaking 47c.
for the adobe programs to run anything smooth it is all about hard drive speed and delegation. If i remember when i did my build adobe recommends a minimum of 4 hard drives, or raids. your system performance hinges on this factor so much. A good setup it one ssd for OS and Adobe only. Raid for video material, export drive/raid, drive for audio and a drive for your audio/video preview files. no spinners under 7200rpm, and if you have the cash use ssd for everything! mandatory for your OS and programs though, it makes everything so snappy.
this is more personal, you said you are a small video editing company, going off that if your doing graphics and such in PP and AE you dont need a workstation graphics card the 780 will do great by itself. Raytrace in AE will tax your gpu memory so get a card with a decent amount. again, that is going off the statement that your a small company and depends on what your doing.
for reference, here is my workstation.
3930k @4.5mhz
noctua u14s in dual fan mode
sabertooth x79 MBO
64gigs gskill z memory
gtx680 4gb
coolermaster 1200w gold+
intel cherryville 128gb ssd, for OS and adobe
Intel 520 ssd for export only. ( i dont recommend this as I have been battling with a problem to export quick time files, everything else works, and qt exports on any other drive just fine.)
WD black 2tb raid0, for visual media only
wd black, 1tb for video preview files
wd balck 1tb for audio files
wd black 1tb for audio preview,
wd balck 1tb for emergency storage, cache and page file.
coolermaster haf 932 adv, with bit fenix fans.
i can handle red 4k single track at full rez, but when i multicam 2 or more red i have to go down to half rez as my system stumbles to keep up.
for ae my raytrace and track works smoothly, speedgrade is also smooth and a pleasure to work with.
render and export times are decent, but i never measured because when i render/export I leave, and go to the store, play a game or take a shower.
so long winded, you need to fill in those parameters from izam.
in summary,
I would for sure ditch the 3960 in favor of the 3930k, and then put the money into hard drives for raid and other purposes.
to save more cash, you could either keep, the workstation graphics card and loose the 780, or keep the 780 and drop the workstation graphics. its up to you and your work really. either way then you could shift money to memory next, adobe will eat all the memory you can throw at it. especially AE ans SG.
a mac pro with comparable specs to mine, when i built it, was something ridiculous like $13k. my system plus 2 proart monitors, adobe cs6 production premium, windows 7 was around $4500.
that is my experience, hope it helps.
esr