4790k + GTX970 is a solid base, just add 16GB or RAM (or 32 if your budget allows), a big SSD (very useful for editing videos), big HDD (to store the videos), good Z97 motherboard, good 650W power supply and a big case.
On a side note, consider going for the workstation class platform with 2011 socket, six-core CPU and DDR4 RAM.