I'm looking for some help setting up a tower stand for this upcoming season. I'm planning on building a tower stand that has a base of 4x8' feet that will either be 4 or 8 feet tall. The tower stand will also be 15-20 feet off the ground. My question is this, what size wood legs would you use? Would a 4x4" be enough?

My second question is how do you go about standing the tower up? Other than sheer man power, I have a skid steer available to help.