For a boat that size, if you've got a yard, you should build a boat storage tube with a lockable door on the end. I've even considered sliding a kayak under the house in the crawl space.
I considered all sorts of hanging and rack schemes for storing two of my kayaks, but I didn't like the idea of having to fool around with lifting them and having them in the way of some of my activities in my shop. My solution was to build a multi-kayak storeage cart. They are stored on padded positions, on edge. The cart has castor wheels and is easy to shuttle around and even out of the shop when necessary. The whole thing was made from one sheet of 3/4" plywood--and a whole shop full of wood working equipment.