I've been out of the loop for a while, so please comment if I've got anything wrong.
I can only buy hardware from ebuyer.com because the system needs to be on his door step by tomorrow, because I'm leaving town on Monday morning.
Asus P8Z68-V PRO Z68 (I picked this due to Quick Sync)
Intel Core i7 2600k 3.4GHz Socket 1155 8MB
Corsair Vengeance 8GB (2x4GB) DDR3 1600Mhz CL9 1.5V Non-ECC Unbuffered (Just some ram that's on the vendor list)
Sapphire HD 6850 Toxic Edition 1GB GDDR5 (Decent bang for buck GPU)
OCZ 60GB Agility 3 SSD (This will have the OS on it)
Corsair TX 650W V2 PSU (decent PSU with plenty of headroom)
Which is more important for the end user? Gaming or Video editing?
If the primary use is going to be editing, rendering and encoding video footage by all means stick with the i7-2600k. If the primary use is going to be gaming, you'll be better off with the i5-2500k and use the saved money to upgrade the graphics card (upgrade to something like 560Ti or 6950).