Based on pre-injury form, GSP wins each category. Boxing is more important IMO when you're also such a good wrestler. Silva can go for his kicks, GSP would most likely take him down even easier.
GSP is the best wrestler for take downs and TDD. And can easily control the fight from top.
With regards to stamina, GSP is able to implement his game play through 5 rounds, and doesn't seem to gas. I can't see how he loses this category, while Silva is an unknown quantity in championship rounds.