Halo, I use a chain leash for neighborhood walks. If you are looking for a long line visit your local saddle shop and look for a lunge line with a stud chain…...ie.
http://www.horsetacksupply.com/pics/lg/1095.jpg there are many varieties and they tend to cost less than a long dog leash. The chain is long enough that if your dog turns his/her head to chew the leash, they encounter chain instead of leather or nylon.
I wish I had advice on the collar but I've not had the problem you have experienced. I use a chain collar when safety is a priority, but they are never worn in the house or yard, just on walkies. The fancy collars are saved for special circumstances like pictures;).
I agree with you, even a slightly chewed leash or collar compromises the safety of your dog, you and your kids if you have to go on a Basenji chase.