Just curious how much that sheet metal cost and where you got it from.

EDIT: Thought I would give some advice for the airflow. Not sure how you have the fans blowing at the end of the card where the dvi ports etc. are, but those should be pulling air away and not blowing on the cards. Then have the ones at the back of the cards pushing air on them. Also, if possible, I would have the case flipped on the side so that the connector side of the cards are pointing up. This should help aid in removing the heat if you follow how I said you should have your fans blowing because heat rises.