I need help on selecting the proper thrust bearing to be used for rotating a guyed-radio tower. The radio tower weighs approximately 20,000 pounds. There are three (3) rotating guy wire rings which allow the guy wires to support the horizontal loads - so the bottom bearing should be primarily axially loaded. I plan on having a steel base plate for the tower to bolt to and a sprocket/chain on the thrust bearing to allow the electric motor torque to rotate the tower. The tower will rotate at approximately 1 rpm. The bearing of course needs to be weather proof and maintenance free. The tower face or width is 24". Any help in type or size would be appreciated.