I'd probably go to B and M / home bargains for a cheap one to see if they like lying on it first, apart from size I would have thought they are all pretty similar in the material the use and the gel inside. If they like it, you could buy multiple or bigger ones. I'm sure mine was only a fiver from there, though it's only medium sizedI don't have cold tiles in my carbut they do work in my kitchen. It only when travelling that I would use a cooling collar or mat.
but they do work in my kitchen. It only when travelling that I would use a cooling collar or mat.