What other ways are there that you have thought of, other than what all the robot in 3 day teams are doing with the wheels, to pickup the ball? Particularly any methods for picking up a ball with a long configuration.
First of all you should let your ball manipulator dictate the general size of your chassis. By building a chassis first you limit what you can do witg the ball.
There are many ways to pick up a ball. You can even look at 2008 robots to see how they did it. The great part about FIRST is you can design most anything you can come up with. Be creative, but make sure it fits your strategy.
Here are some ways that teams have interacted with large balls in past seasons.