Pot Saucers for 30 gallon smart pot

I have been shopping around for some pot saucers that will hold a 30 gallon smart pot with no luck. The pots are 24 inches in diameter so I need something that is like 28 to hold it comfortably. Any suggestions or solutions would be greatly appreciated.

kiddie pool?

giant pizza pan?

OH HEY! WHAT ABOUT ONE OF THOSE SAUCERS FOR SLEDDING!!

these are the largest saucers i've come across:

http://www.roguehydro.com/super-garden-saucer-25/

How about the flat top of a brute garbage can? Just invert it and you're good to go

Edit: I think they're 45gallon cans will be big enough, just the top though.