I like the height of a 5gal paint bucket ($3 at the local hardware store). Its a few inches lower than the typical 7gal ball bucket. I added a padded lid from a broken ball bucket to complete the package.
Padded cushion!? How about lining the inside and making it into a cooler for uhhh..., water? I saw a bucket the other day that had speakers in the side and a place to plug in his iPhone for tunes!