Couple things I a found worthwhile to do when you go to Big D for a game...
1. Do the Texas Stadium tour if you haven't done so before...even if its just to get on the field. My buddies and I loved kicking FG's and running pass patterns on the field.
2. Go to the Marriott where they stay the night before the game around 7pm as they have to check in the night before. Also go the morning before as they leave. You will meet alot of former and current Cowboys in the lobby and in the parking lot that you can get autographs from!
Dondy know about Randys restaurant, but the guy is nice. Met him a a signing last year. chats with you and is always pleased to meet fans/sign items.