I think it would be best if you and your league came up with your own constitution. That way it will be entirely applicable to your group.
To create my league's constitution, I came up with a list of issues that I thought needed to be put under the microscope and held a live meeting with my league in order to discuss them (you could also email them to members). With everyone's agreement and input, I then wrote up our constitution.
Mike Pelfrey > Matt Garza