This post would suggest you'd get 200-300 MH/s per card.
You can use a
profit calculator to see if you break even. You need to look at total power costs as well. However with more ASICs coming online you will find it hard to make a profit. Look at mining Litecoin and using
cudaMiner.
At current difficulty, 500 MH/s would produce an average of
BTC0.85 a month before costs.