I think the case will work.
It is a nice, well ventilated case, just not a lot of fans.
I assume you own it, otherwise, there are better cooling lian li cases available.
If you only need one external 5 1/2" bay, you could add a front intake 120mm intake fan.
Something like this:http://www.newegg.com/Product/Product.aspx?Item=N82E16811999164&cm_re=bay_fan-_-11-999-164-_-Product
I think scythe also makes a simpler, and cheaper version called kama bay.
For sli, pay particular attention to the motherboard, and where the two pcie-x16 slots are located.
In many motherboards, the two cards will be located next to each other, and the top card will run hot.
Find a motherboard where the slots have a bit more separation.
If you own the GTX460cards, then fine. If not, I think things would be simpler using a single stronger card.
Also, why the i7-950? Sandy bridge cpu's are much stronger and cheaper. A basic 2400 can compete with a i7-980.
A 2500K with a mild OC would be much better.
For your editing, you could get a full 16gb(4 x 4gb)