Looks & sounds cool. One thought.. If I were building this, I'd make sure to engineer it with a strong post in the center of each wall and then a really strong beam spanning the width of the bay with the beam resting on the posts. Then, at any time in the future you could install a hoist: chain or electric. That way you can lift anything you need to: an engine, lift an implement & set it on a dolly, partially lift a mower or cutter to remove the blades for sharpening, etc.