You'll have all the fitness you need if you're doing 40 km crits (or training for them). You'll probably want to work on sustained speed on a fixed gear-- motorpacing or pacing behind faster riders is good for that. With races this short it's going to be as much about position as anything else, unless there's such a huge range in abilities that someone can just ride away. And how do you do a 9 lap points race? Is it a tempo race?