Just buy a roll of twine. For one thing you get a lot for super cheap. You could have something more permanent that costs more, but it would be a pain when harvesting time comes. I don't imagine you have a cherry picker or something. You'd have to stand up there with your ladder or whatever and pick the vine for a while. If using twine you just cut it and the hop vine where it meets the ground and top support, take the whole piece, then sit on the ground with a bucket and tarp laid out picking away. Much more comfortable that way than being up high for a long time. Something more permanent would require unraveling the vine from it, then taking it down and harvesting unless you have some way of staying up there.