i was not sure where to put this thread wise. we have 2 van ness litter boxes with high sides and 3 of our cats are pretty big church is almost 15lbs and chocolate is 14lbs and peekaboo is 11lbs they all have big bone structures and we need to get high sided boxes cause they do like to throw litter about lol. is the van ness giant high sided box the biggest they make? it has to be longer and a little wider as well much apreciate the help.