With a budget like this, you should go with a setup that will allow overclocking in the future. It is very easy and could prolong upgrading your CPU for a year or more. Z68 boards aren't out yet, but that will be what you want for Quick Sync (ridiculously fast encoding times). We'll set aside $220 in the budget for that.
* You could drop 8GB of ram to free up some money for a small SSD. Z68 allows SSD caching which speeds things up a bit. Here's an article by Tom's to get you up to speed. It also goes into detail about the Z68 chipset's advantages over P67 and touches on Quick Sync (link).