I can't answer your question (I don't know) but building a wire cage isn't that difficult. I've done this before. All you need is the right hardware, some good pliers and cutters, and a metal file to round off sharp edges from cutting. Usually you can find all the parts at a hardware store that caters to agriculture. It's not a pretty as a FN cage but it works just as good if you find you can't get what you are looking for.
