First time building a pc need help 800$ budget

Motherboards : BIOSTAR TZ68A+ LGA 1155 Intel Z68
http://www.newegg.com/Product/Product.aspx?Item=N82E16813138319 110$
ASRock Z68 Extreme3 Gen3
http://www.newegg.com/Product/Product.aspx?Item=N82E16813157271 122$
Power supply :
Antec NEO ECO 620C 620W
http://www.newegg.com/Product/Product.aspx?Item=N82E16817371031 50$ after rebates
Video card :
SAPPHIRE Radeon HD 6870 1GB 256-bit GDDR5
http://www.newegg.com/Product/Product.aspx?Item=N82E16814102948 170$ and 150$ after rebates.
GIGABYTE GeForce GTX 560 Ti
http://www.newegg.com/Product/Product.aspx?Item=N82E16814125401 210$