From what Google tells me, bacon ribs are a product of curing pork and the attached ribs like bacon. The ribs are then separated and sold by butchers in the UK. It sounds like their use is similar to a ham hock or salt pork (boiling for flavor in soups, stock, etc).
I only found one online source, and I'm not sure if they ship to the US:
I'm curious why bacon ribs would be worth the expense and effort over using a ham bone or even a slab of bacon?