They will definately grow 40 ft in a season and if you don't guide them vertically, you're in trouble. I'm speaking from experience here.

I kind of have a hinged ladder system in my head. From what I understand, you can get them going in a spiral and they will train to continue. Then I was thinking of putting a hinge point to fold down within ladder reach, so that I can get to all the cones.
Found this cool looking source also.
http://www.freshops.com/rhizinfo.html