1/4" phone plug to spade lugs

You might have to do it yourself. Get a speaker cable of the right length with a phone plug on one end, and then a couple of spade lugs, unsolder the other phone plug and then put the spade lugs on. I remember some speaker cables coming with those spade-lug looking connectors with the curled edges that you just push on. I've also just soldered the bare wires onto the posts.