Satellite dish for Astronomy project. (Bloxwich WS3)

Project to use a satellite dish, turn it into a radio-telescope. And then map the arms of the milky-way galaxy using the 1420Mhz radio waves we collect.
    Dish required, all other bits will get recycled as we have to fit, new sensors and cables. Dish needs to be 'OVER 1MTR IN DIAMETER' to be able to recieve the 21cm radio waves at 1420Mhz . [Google it, actually intereseting but long-winded] Amateur Astronomist....