Will be overclocking, liquid cooling preferred.
Willing to wait for Pascal.
Air 240 or Air 540 preferred
As no one know any true details let alone prices on Pascal it is impossible to currently spec it.
I know that, just saying that I'm willing to wait.
I don't have to
This will give you an idea..
PCPartPicker part list / Price breakdown by merchant
Sorry to burst your bubble, but a X99 system for $1200 is nearly impossible to have something halfway decent. Anyways, here's what I could make up for video editing purposes, and 1440P gaming.
You don't need to have the storage like this, but something configured like this should be completely fine for video editing. A SSD for the actual edit of the video, and the 4TB HDD for archival purposes. That drive is slow, but you probably won't be accessing it too often, so it shouldn't matter too much.