Build for video editing

Hi im trying to build a computer for video editing purposes only. I will be doing no gaming at all. I am trying to keep the price fairly low but i do want to get the the best bang for my buck. For starters this is what i have chosen, i will eventually upgrade as time goes on.


Intel BOXDZ68BC LGA 1155 Intel Z68 HDMI SATA 6Gb/s USB 3.0 ATX Intel
www.newegg.com/Product/Product.asp [...] 6813121533

Intel Core i5-2500K Sandy Bridge LGA 1155

G.SKILL Ripjaws X Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 1600 (PC3 12800) Desktop Memory Model
www.newegg.com/Product/Product.asp [...] 6820231428

Mushkin Enhanced Chronos MKNSSDCR120GB 2.5" 120GB SATA III MLC Internal Solid State Drive (SSD)
www.newegg.com/Product/Product.asp [...] 6820226236

SAMSUNG Spinpoint F3 HD103SJ 1TB 7200 RPM SATA 3.0Gb/s 3.5" Internal Hard Drive -Bare Drive
www.newegg.com/Product/Product.asp [...] 6822152185

1. Should i stick with the z68 chip-set or go with the p67? or which one would i benefit from the most if Im just using the system for HD editing? (note that i switch from Sony vegas10 and adobe CS5.5)
2. I know the i7 is better but will there be a great difference in performance if i go with the i5?
3. I haven't chosen a graphics card yet, Im am just curious to know which one this system will benefit from the most?

the z68 is good because you can benefit from smart response technology