What you could do is buy the single 6970 for right now, spend $199.99 on the ACER 24inch 2ms response time 1920x1080 resolution monitor.
When BF3 releases, pick up your second 6970.
You should look into getting a Crucial M4 128gb SSD its a beast @ $219.99
I plan on picking up a second msi 6950 tf3 for my pc when bf3 releases so yeah ^_^
The psu you should get to power the 6970's (great product)
http://www.newegg.com/Product/Product.aspx?Item=N82E16817194093
If I hadn't purchased my TX850W corsair enthusiast psu already I would have bought two of these with the price I paid for mine + a few extra dollars lol >_>