ASk in the Premier forum for better answers, but since most footage handling uses the GPU in some way, the difference should be negligible. Even under ideal conditions this would be somthing like a 5% boost, but most of the time you wouldn't notice anything.
I beg to differ. 6-cores versus 4-cores is an immense difference with the very CPU intensive media you intend handling. Also the i7-4770K as a chip by itself at Newegg is $310 versus the i7-4930K is $575 that is only $265 difference for the CPU. You may be talking complete system price.
Also you will be using a 2011 pin socket which will probably have a longer lifetime than the 1150 pin socket. Another major advantage is four channel memory with a maximum memory of 64 GB which you might want if you get into serious AE work.
For future expansion the i7-4930K has 40 PCIe lanes where the i7-4770k has only 16 lanes, once you install that GTX 770 you have no more PCIe expansion unless you want to down grade your GPU to run at x8.
R3D 4K uses the GPU accelerated debayering in CC. This requires far more processing than before to get the data to the GPU efficiently. You need a 6 core and 32GB of ram minimum to handle that realtime well. I suggest you go with the 6 core. I would also suggest an X99 system which is i7 Gen 4 versus the X79 which is i7 Gen 3. DDR4 makes a huge impact on GPU acceleration with CC especially with R3D 4K media.