SSD: Samsung 840 Pro 120GB. $150 http://www.newegg.com/Product/Product.aspx?Item=N82E168...
I recommend this with a bit of reluctance, its fairly expensive for an SSD of its capacity. I would rather advise a Samsung 830, but it seems they are disappearing from stock now that the 840 series is out, and unfortunately they are of lower quality than their predecessors. The 840 is about the best SSD on the market, but I personally dont think its worth the extra $40 you pay. If you can find a 128GB 830 somewhere else, I advise you get that.
Total (With Corsair case, before rebates and shipping): $1160
That leaves you enough cash to throw in a workstation card of some sort, while being a fairly good rig.
The reason for two hard drives (and the SSD) is to distribute the load. The SSD has Windows and your important programs on it, one HDD holds all the raw footage or resources your dealing with in an editing application, while the other HDD acts as the output drive for when your rendering. This is so no one drive is reading and writing data at the same time, which can slow things down a fair bit.
Your unimportant programs, general files (movies, music, documents) and such can be put on the output drive to no ill effect.