if gaming and video editing is the highest priority then going i7 2600k or the new i7 3770k(sold out atm) will do the job.
if you are not interested in overclocking then going w/o the k will be more efficient for the price
PSU: go for a Seasonic 620 modular. this supply will keep your needs clean which means better airflow
GPU:a 7850 will do the job for a while if you want to upgrade to a 670 that will work to but you might need to increas your budget.
CASE: i love rocking with a nice case but it seems a 500R is out of your price range
http://www.newegg.com/Product/Product.aspx?Item=N82E16811146090
$30 cheaper than a 500R i just like the white color on cases because i have seen to much black cases.
MOBO: just forgot about something there is a sale for a 500R with a good mobo i would love recommending this
http://www.newegg.com/Product/Product.aspx?Item=N82E16811146090
RAM: i like going with a 8GB @ 1600 speed ram but since you are doing video rendering going to a 16 GB ram might be a better choice try to go for one with low heat sinks
i recommend going with CORSAIR VENGEANCE
this one has room for you to upgrade to more RAM if you need
http://www.newegg.com/Product/Product.aspx?Item=N82E16820233280
this one is cheaper but won't let you upgrade to something higher later
http://www.newegg.com/Product/Product.aspx?Item=N82E16820233197