Hello Tesseract,
My thoughts on the information you provided are, going vertical is a great way to maximize space.
led's, well glad your rich. I cant wait 5-10 years to break even making back all the money in energy savings I shelled out up front to grow with LED's. A vertical light in the center? I don't know how you plan to design the system/s and/or what plants you plan to grow, but if the light is to the side of the plant's you may have a problem with the plants trying to grow sideways instead of upward. That may even lead to stability problems. I would use pond and fountain pumps instead of sump pumps. Far less costly and in most cases more water flow as well.