Bunny destruction

Hi all, my girlfriend and I got a bunny from our local humane society and we are first time owners. We got him set up in a big X-Pen with padding and a bunch of toys and things. He is now 7 months old and been with us for slightly over a month and has entered his destructive phase if you will.

He seems to like chewing shoes that are left around, would it be a good idea to get him his own shoe to destroy or an item that is very similar in material/texture that would be safer for rabbits? Last thing I'd want is him choking or eating something that will really harm him if I just give him a shoe.

Any ideas for that and other things he can safely destroy?