You need a large tray, buy 2, screw one down and pop the other one inside it
I use shavings in the trays (horse stuff thats dust extracted, i used to get shavings for free but they were dusty as hell and made me sneeze never mind the ferrets.
For bedding I use blankets, bang them in the washer every week or so, they love em, saves me spending on straw etc. (but rinse washer out after LOL, one mistake i made once )