Yeah I have one it's fine it can fit any size card so long as you don't have the middle cage filled with HDDs or a middle fan. I currently have 5850s and a center fan in the cage, it's close but even that fits. Without the fan there's another 6 or more inches to go lol.
Ok but i'm a little concerned about the airflow of 2 SLI GTX 470.
Do you recommened going for the Antec 1200 or stick with 902
It shouldn't be a problem unless the PCI-e slots on your motherboard are right beside eachother. Even then, the addition of a fan blowing air in at them from the HDD bays should provide enough additional airflow.
The 902 has great airflow, especially if you add the optional fans. And the ASUS mobo also has nice spacing, allowing for about an inch of clearance between the cards so the top one won't heat up so bad.