Best covered litter tray for Maine Coons?

What covered litter tray do you use for your Maine coon cat? Using a large plastic box is ok for us but as its in the kitchen area we would like to get a covered one. Obviously due to the kitties large size a regular one wouldnt cut it, ive had a look online and a couple of people of said about using a Booda Cleanstep tray but it just doesnt seem big enough as most of its taken up by the steps. So i need advice from Coon owners, what do you use as a covered tray?