Martin, I stumbled across your post from a few years ago. Did you ever get your hands on some Comfrey? If not, I would happily send you some roots.
Both sunchokes and comfrey could easily take over the world...or at least the PNW. With either, if you plant them in the ground, it is very hard to get rid of them. Both will continue to spread outward until they reach some sort of barrier, so do be sure you have them where you want them. :) Along the parking strip sounds like a great place for the sunchokes.
Have fun with your urban garden!
