Cats are especially hard to secure (vs a traditional
monohull w limited ingress/egress points).
Given all the expanses of windows/sliding doors/hatches, you can go with a ploycarbonate (AKA Lexan), but they tend to go cloudy w UV exposure. There are some which have UV resistant coatings, but still eventually go cloudy. Last time I used such a prodcut was over a decade ago, it went cloudy in a few years. Maybe there are some better coatings now. If anyone knows of such, would love to hear about it.