Something to think about, even though this is "solved". Cards that SLI must have the same model number, for SLI to work. Cards that crossfire (ATI Cards) can be different models. So, if in the future, you find that the card you have, is not cutting the mustard, you can upgrade to another ATI card, 69xx or 7xxx series, and still do crossfire, getting longer use out of your current card, and boosting the performance of your newer card.
Just something to think about. Good luck with your system.