For mine I used baltic birch plywood for the bed and dimensional birch for the brackets. The tubular track is glued to Woodland Scenics foam under layment which is glued to the birch. I used the birch because it gives you a nice clean edge for a nice poly finish. If I were to do it again the only real change woud be to make the shelf all the way to the wall to give you the ability to do some scenery, whether it just be some back drops or backdrops and building facades.
Ceiling brackets where it passes in front of the closet doors.