If you decide to keep the plastic pans, I would get fleece liners that act as a "pillow case" rather than just sit in the pan. With those types of liners, you can slip the plastic pan inside the liner so the chins can't get to them.
I was using a fleece liner over a plastic pan until my bass pan came in the mail..my chin pulled the fleece over and started chewing on the pan, and he actually got an impaction in his intestines by the plastic that he ingested. Thankfully he was okay.